Veracyte (VCYT) 10-K25 Feb 202019 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2019	Feb. 20, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-36156
Entity Registrant Name	VERACYTE, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	20-5455398
Entity Address, Address Line One	6000 Shoreline Court,
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	South San Francisco,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	650
Local Phone Number	243-6300
Title of 12(b) Security	Common Stock, par value, $0.001 per share
Trading Symbol	VCYT
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 1.3
Entity Common Stock, Shares Outstanding		49,738,822
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Portions of the registrant's proxy statement to be filed with the Securities and Exchange Commission in connection with the solicitation of proxies for the registrant's 2020 Annual Meeting of Stockholders to be held on or about June 5, 2020 are incorporated herein by reference in Part III of this Annual Report on Form 10-K to the extent stated herein. Such proxy statement will be filed with the Securities and Exchange Commission within 120 days of the registrant’s fiscal year ended December 31, 2019.
Entity Central Index Key	0001384101
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 159,317	$ 77,995
Accounts receivable	19,329	13,168
Supplies	6,806	3,402
Prepaid expenses and other current assets	2,235	2,387
Total current assets	187,687	96,952
Property and equipment, net	8,933	8,940
Right-of-use assets - operating lease	8,808	0
Finite-lived intangible assets, net	65,019	12,000
Goodwill	2,725	1,057
Restricted cash	603	603
Other assets	1,437	1,086
Total assets	275,212	120,638
Current liabilities:
Accounts payable	2,328	2,516
Accrued liabilities	13,734	9,186
Current portion of long-term debt	0	1,357
Current portion of operating lease liability	1,407	0
Total current liabilities	17,469	13,059
Long-term debt	694	23,925
Deferred rent, net of current portion	0	3,899
Acquisition related contingent consideration	6,088	0
Operating lease liability, net of current portion	11,506	0
Total liabilities	35,757	40,883
Commitments and contingencies
Stockholders' equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized, no shares issued and outstanding as of December 31, 2019 and 2018	0	0
Common stock, $0.001 par value; 125,000,000 shares authorized, 49,625,341 and 40,863,202 shares issued and outstanding as of December 31, 2019 and 2018, respectively	50	41
Additional paid-in capital	486,090	313,800
Accumulated deficit	(246,685)	(234,086)
Total stockholders' equity	239,455	79,755
Total liabilities and stockholders' equity	$ 275,212	$ 120,638

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized	125,000,000	125,000,000
Common stock, shares issued	49,625,341	40,863,202
Common stock, shares outstanding	49,625,341	40,863,202

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Total revenue	$ 120,368	$ 92,008	$ 71,953
Operating Expenses:
Cost of testing revenue	36,077	33,078	28,195
Cost, Direct Material	446	0	0
Research and development	14,851	14,820	13,881
Selling and marketing	53,691	41,313	32,260
General and administrative	29,029	23,963	23,088
Intangible asset amortization	1,401	1,067	1,067
Total operating expenses	135,495	114,241	98,491
Loss from operations	(15,127)	(22,233)	(26,538)
Interest expense	(677)	(1,963)	(4,941)
Other income, net	3,205	1,197	476
Net loss	(12,599)	(22,999)	(31,003)
Comprehensive loss	$ (12,599)	$ (22,999)	$ (31,003)
Net loss per common share, basic and diluted (in dollars per share)	$ (0.27)	$ (0.62)	$ (0.91)
Shares use to compute net loss per common share, basic and diluted (in shares)	46,138,177	37,020,246	33,925,617
Testing revenue
Total revenue	$ 107,355	$ 91,058	$ 71,953
Product revenue
Total revenue	923	0	0
Biopharmaceutical revenue
Total revenue	8,090	950	0
Collaboration revenue
Total revenue	$ 4,000	$ 0	$ 0

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Balance at Dec. 31, 2016	$ 59,581	$ 34	$ 239,631	$ (180,084)
Balance (in shares) at Dec. 31, 2016		33,762,278
Increase (Decrease) in Stockholders' Equity [Rollforward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units	1,374		1,374
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		295,059
Issuance of common stock under employee stock purchase plan (ESPP)	656		656
Issuance of common stock on employee stock purchase plan (ESPP) (in shares)		153,051
Stock-based compensation expense (employee)	6,352		6,352
Stock-based compensation expense (non-employee)	19		19
Stock-based compensation expense (ESPP)	246		246
Net loss	(31,003)			(31,003)
Net loss and comprehensive loss	(31,003)
Balance at Dec. 31, 2017	37,225	$ 34	248,278	(211,087)
Balance (in shares) at Dec. 31, 2017		34,210,388
Increase (Decrease) in Stockholders' Equity [Rollforward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units	3,433	$ 1	3,432
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		756,231
Issuance of common stock under employee stock purchase plan (ESPP)	790		790
Issuance of common stock on employee stock purchase plan (ESPP) (in shares)		146,583
Sale of common stock in a private placement, net of issuance costs	55,038	$ 6	55,032
Sale of common stock in a private placement, net of issuance costs (in shares)		5,750,000
Stock-based compensation expense (employee)	5,602		5,602
Stock-based compensation expense (non-employee)	24		24
Stock-based compensation expense (ESPP)	332		332
Legal settlement from short-swing profits, net of tax	310		310
Net loss	(22,999)			(22,999)
Net loss and comprehensive loss	(22,999)
Balance at Dec. 31, 2018	79,755	$ 41	313,800	(234,086)
Balance (in shares) at Dec. 31, 2018		40,863,202
Increase (Decrease) in Stockholders' Equity [Rollforward]
Issuance of common stock on exercise of stock options and vesting of restricted stock units	13,378	$ 2	13,376
Issuance of common stock on exercise of stock options and vesting of restricted stock units (in shares)		1,924,156
Issuance of common stock under employee stock purchase plan (ESPP)	1,266		1,266
Issuance of common stock on employee stock purchase plan (ESPP) (in shares)		136,251
Sale of common stock in a private placement, net of issuance costs	137,848	$ 6	137,842
Sale of common stock in a private placement, net of issuance costs (in shares)		6,325,000
Issuance of common stock for acquisition	10,000	$ 1	9,999
Issuance of common stock for acquisition (in shares)		376,732
Stock-based compensation expense (employee)	8,883		8,883
Stock-based compensation expense (non-employee)	181		181
Stock-based compensation expense (ESPP)	743		743
Net loss	(12,599)			(12,599)
Net loss and comprehensive loss	(12,599)
Balance at Dec. 31, 2019	$ 239,455	$ 50	$ 486,090	$ (246,685)
Balance (in shares) at Dec. 31, 2019		49,625,341

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Statement of Stockholders' Equity [Abstract]
Issuance costs	$ 9,208	$ 3,890

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net loss	$ (12,599)	$ (22,999)	$ (31,003)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,117	3,920	3,841
(Gain) loss on disposal of property and equipment	(23)	0	12
Stock-based compensation	9,807	5,958	6,617
Other income	0	(93)	0
Amortization and write-off of debt discount and issuance costs	83	32	472
Interest on end-of-term debt obligation and prepayment penalty	229	312	1,589
Changes in operating assets and liabilities:
Accounts receivable	(6,161)	(452)	(3,960)
Supplies	(3,404)	1,922	(1,849)
Prepaid expenses and other current assets	154	(517)	(7)
Right-of-use assets - operating lease and operating lease liability	(171)	0	0
Other assets	(351)	(760)	(192)
Accounts payable	(141)	(1,568)	1,728
Accrued liabilities and deferred rent	5,228	724	(1,163)
Net cash used in operating activities	(3,232)	(13,521)	(23,915)
Investing activities
Cash paid for acquisition	(40,000)	0	0
Purchases of property and equipment	(2,756)	(1,874)	(1,755)
Proceeds from the sale of property and equipment	23	0	440
Net cash used in investing activities	(42,733)	(1,874)	(1,315)
Financing activities
Proceeds from the issuance of long-term debt, net of debt issuance costs	0	0	24,880
Proceeds from issuance of common stock in a public offering, net of issuance costs	137,848	55,038	200
Payment of long-term debt	(24,900)	0	(25,385)
Payment of end-of-term debt obligation and prepayment penalty	0	0	(1,536)
Proceeds from legal settlement regarding short-swing profits	0	403	0
Payment of financial lease liability	(308)	(292)	(274)
Proceeds from the exercise of common stock options and employee stock purchases	14,647	4,350	1,897
Net cash provided by (used in) financing activities	127,287	59,499	(218)
Net increase (decrease) in cash, cash equivalents and restricted cash	81,322	44,104	(25,448)
Cash, cash equivalents and restricted cash at beginning of year	78,598	34,494	59,942
Cash, cash equivalents and restricted cash at end of year	159,920	78,598	34,494
Supplementary cash flow information of non-cash investing and financing activities:
Operating lease liability arising from obtaining right-of-use assets - operating lease at beginning of period	14,118	0	0
Shares issued for purchase consideration for a business combination	10,000	0	0
Deferred purchase consideration for a business combination	6,088	0	0
Purchases of property and equipment included in accounts payable and accrued liabilities	226	273	42
Supplementary cash flow information:
Cash paid for interest on debt	332	1,547	2,718
Cash paid for tax	35	79	21
Total cash, cash equivalents and restricted cash	$ 159,920	$ 34,494	$ 59,942

Organization and Description of

Organization and Description of Business	12 Months Ended
Organization and Description of Business	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business Veracyte, Inc. (“Veracyte” or the “Company”) is a leading genomic diagnostics company that is creating value through innovation. The Company was founded in 2008 with a mission to improve diagnostic accuracy. Today, the Company's growing menu of tests leverage advances in genomic science and technology to improve care throughout the patient journey, enabling more confident diagnostic, prognostic and treatment decisions in cancer and other challenging diseases. The Company is creating new standards of care by enabling more patients to avoid risks of unnecessary invasive procedures and removing costs from the healthcare system, while speeding the time to diagnosis and treatment decisions. Veracyte was incorporated in the state of Delaware on August 15, 2006 as Calderome, Inc. Calderome operated as an incubator until early 2008. On March 4, 2008, the Company changed its name to Veracyte, Inc. The Company’s operations are based in South San Francisco, California and Austin, Texas, and it operates in one segment. The Company performs its genomic tests for thyroid cancer, lung cancer and idiopathic pulmonary fibrosis, or IPF, in our CLIA-certified laboratory in South San Francisco, California. In December 2019, we announced our acquisition of the exclusive global diagnostics license to the NanoString nCounter FLEX Analysis System, as well as the Prosigna breast cancer prognostic gene signature assay, which is commercially available, and the LymphMark lymphoma subtyping assay, which is in development. Both tests are designed for use on the nCounter system. The Company offers genomic tests in thyroid cancer; lung cancer; IPF and breast cancer: Afirma Genomic Sequencing Classifier and Xpression Atlas. The Company's Afirma offerings include the Afirma GSC and Xpression Atlas, to help guide next steps for patients with potentially cancerous thyroid nodules. The offerings are intended to provide physicians with clinically actionable results from a single fine needle aspiration, or FNA biopsy. The Afirma GSC was developed with RNA whole-transcriptome sequencing and machine learning, and is used to identify patients with benign thyroid nodules among those with indeterminate cytopathology results in order to rule out unnecessary thyroid surgery. The Company commercially launched the Afirma Xpression Atlas in 2018 to complement the Afirma GSC. The Xpression Atlas provides physicians with genomic alteration content from the same FNA samples that are used in Afirma GSC testing and may help physicians decide with greater confidence on the surgical or therapeutic pathway for their patients. Percepta Genomic Sequencing Classifier. The Percepta classifier improves lung cancer diagnosis by enhancing the performance of diagnostic bronchoscopies, thus identifying more patients with lung nodules who are at low risk of cancer and may avoid further, invasive procedures. This second-generation test was developed on our RNA whole-transcriptome sequencing platform and commercially introduced in June 2019, provides expanded clinical utility by also identifying patients as high risk of cancer so they may obtain faster diagnosis and treatment. The test is built upon foundational "field of injury" science - through which genomic changes associated with lung cancer in current and former smokers can be identified with a simple brushing of a person's airway - without the need to sample the often hard-to-reach nodule directly. Envisia Genomic Classifier. The Envisia classifier improves diagnosis of IPF by helping physicians better differentiate IPF from other interstitial lung diseases, or ILDs, without the need for surgery. The test identifies the genomic pattern of usual interstitial pneumonia, or UIP, a hallmark of IPF, with high accuracy on patient samples that are obtained through transbronchial biopsy, a nonsurgical procedure that is commonly used in lung evaluation. Prosigna Breast Cancer Prognostic Gene Signature Assay . The Prosigna test, acquired in December 2019 through our strategic transaction with NanoString, uses advanced genomic technology to inform next steps for patients with early-stage breast cancer, based on the genomic make-up of their disease. The test leverages a collection of 50 genes known as the PAM50 gene signature and can provide a breast cancer patient and physician with prognostic score that indicates the probability of cancer recurrence over ten years. Physicians use Prosigna to help guide therapeutic decisions so that patients receive a therapeutic intervention, such as chemotherapy, only if clinically warranted. The Company’s approach also provides multiple opportunities for partnerships with biopharmaceutical companies. In developing the Company's products, the Company has built or gained access to unique biorepositories, proprietary technology and bioinformatics that it believes are important to the development of new targeted therapies, determining clinical trial eligibility and guiding treatment selection. All of the Company's testing services are made available through its clinical reference laboratories located in South San Francisco, California and Austin, Texas.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The Company's consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States ("U.S. GAAP"). The consolidated financial statements include the accounts of the Company and its wholly-owned subsidiary, which was created in 2019 to process certain administrative functions associated with the business combination in Note 4, Business Combination. All intercompany accounts and transactions have been eliminated in consolidation. Certain amounts have been reclassified on the consolidated statements of operations for presentation purposes. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant items subject to such estimates include: revenue recognition; the useful lives of property and equipment; the recoverability of long-lived assets; the estimation of the fair value of intangible assets; stock options; income tax uncertainties, including a valuation allowance for deferred tax assets; and contingencies. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recognized revenue and expenses that are not readily apparent from other sources. Actual results could differ from those estimates and assumptions. Liquidity The Company has incurred net losses since its inception and as of December 31, 2019 , the Company had an accumulated deficit of $246.7 million . The Company believes its cash and cash equivalents of $159.3 million as of December 31, 2019 and its revenue from sales in 2020 will be sufficient to meet its anticipated cash requirements through at least February 2021. On May 7, 2019, the Company issued and sold 6,325,000 shares of common stock in a registered public offering, including 825,000 shares issued and sold upon the underwriters’ exercise in full of their option to purchase additional shares, at a price to the public of $23.25 per share. The Company's net proceeds from the offering were approximately $137.8 million , after deducting underwriting discounts and commissions and offering expenses of $9.2 million . In July 2018, the Company issued and sold 5,750,000 shares of common stock in a registered public offering, including 750,000 shares issued and sold upon the underwriters' exercise in full of their option to purchase additional shares, at a price to the public of $10.25 per share. The Company's net proceeds from the offering were approximately $55.0 million , after deducting underwriting commissions and offering expenses of $3.9 million . In November 2017, the Company entered into a Loan and Security Agreement and drew down a term loan advance of $25.0 million of which the entire amount was used to pay the outstanding balance of the Company's previous long-term debt as discussed in Note 8 - Debt. If the Company is not able to generate cash proceeds from revenue sufficient to satisfy its cash obligations, the Company will need to finance future cash needs primarily through public or private equity offerings, debt financings, borrowings or strategic collaborations or licensing arrangements. If the Company is not able to secure additional funding when needed, on acceptable terms, it may have to delay, reduce the scope of or eliminate one or more research and development programs or selling and marketing initiatives which may have a material adverse effect on the Company's business, results of operations, financial condition and/or its ability to fund its scheduled obligations on a timely basis or at all. Concentrations of Credit Risk and Other Risks and Uncertainties The majority of the Company's cash and cash equivalents are deposited with one major financial institution in the United States. Deposits in this institution may exceed the amount of insurance provided on such deposits. The Company has not experienced any losses on its deposits of cash and cash equivalents. Several of the components of the Company's sample collection kit and test reagents, and its nCounter FLEX DX systems and related test kits are obtained from single-source suppliers. If these single-source suppliers fail to satisfy the Company's requirements on a timely basis, it could suffer delays in being able to deliver its diagnostic solutions, a possible loss of revenue, or incur higher costs, any of which could adversely affect its operating results. The Company is also subject to credit risk from its accounts receivable related to its sales. The Company does not perform evaluations of customers' financial condition and does not require collateral. Through December 31, 2019 , most of the Company's revenue have been derived from the sale of Afirma. To date, Afirma has been delivered primarily to physicians in the United States. The Company's third-party payers and other customers in excess of 10% of revenue and their related revenue as a percentage of total revenue were as follows: Year Ended December 31, 2019 2018 2017 Medicare 26 % 29 % 26 % UnitedHealthcare 11 % 12 % 14 % 37 % 41 % 40 % The Company's significant third-party payers and other customers in excess of 10% of accounts receivable and their related accounts receivable balance as a percentage of total accounts receivable were as follows: As of December 31, 2019 2018 Medicare 15 % 20 % Johnson and Johnson Services, Inc. 10 % — % UnitedHealthcare 9 % 11 % Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consist of amounts invested in a money market account primarily consisting of U.S. Treasury reserves, and overnight reverse repurchase agreements which are tri-party repurchase agreements and are collateralized by U.S. Treasury and agency securities of at least 102% of the principal amount. In a tri-party repurchase agreement, a third-party custodian bank functions as an independent intermediary to facilitate transfer of cash and holding the collateral on behalf of the underlying investor for the term of the agreement thereby minimizing risk and exposure to both parties. These overnight reverse repurchase agreements are included within cash equivalents due to their high liquidity and relatively low risk. Restricted Cash The Company had deposits of $603,000 included in long-term assets as of December 31, 2019 and December 31, 2018 , restricted from withdrawal and held by a bank in the form of collateral for an irrevocable standby letter of credit held as security for the lease of the Company's South San Francisco facility. Acquisitions The Company first determines whether a set of assets acquired and liabilities assumed constitute a business and should be accounted for as a business combination. If the assets acquired are not a business, the Company accounts for the transaction as an asset acquisition. Business combinations are accounted for by using the acquisition method of accounting. Under the acquisition method, assets acquired, and liabilities assumed are recorded at their respective fair values as of the acquisition date in our consolidated financial statements. The excess of the fair value of consideration transferred over the fair value of the net assets acquired is recorded as goodwill. Contingent consideration obligations incurred in connection with a business combination are recorded at fair value on the acquisition date and remeasured at each subsequent reporting period until the related contingencies are resolved, with the resulting changes in fair value recorded in earnings. Accounts Receivable and Allowance for Doubtful Accounts for Product Sales Accounts receivable are stated at the amount management expects to collect from customers based on their outstanding invoices. Management reviews accounts receivable regularly to determine if any receivable will potentially be uncollectible and to estimate the amount of allowance for doubtful accounts necessary to reduce accounts receivable to its estimated net realizable value by analyzing the status of significant past due receivables. Product sales commenced in December 2019 and there was no allowance for doubtful accounts at either December 31, 2019 or 2018. Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally between three and five years . Leasehold improvements are amortized using the straight-line method over the shorter of the estimated useful life of the asset or the term of the lease. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in the statements of operations and comprehensive loss in the period realized. Finite-lived Intangible Assets Finite-lived intangible assets consist of intangible assets acquired as part of business combinations. The Company amortizes finite-lived intangible assets using the straight-line method over their estimated useful lives of 5 to 15 years , based on management's estimate of the period over which their economic benefits will be realized, product life and patent life. The Company tests these finite-lived intangible assets for impairment when events or circumstances indicate a reduction in the fair value below their carrying amounts. There was no impairment for the years ended December 31, 2019 , 2018 or 2017 . Goodwill Goodwill, derived from the Company's acquisition of Allegro Diagnostics Corp. in September 2014 and the exclusive global diagnostics license to the NanoString nCounter FLEX Analysis System and Prosigna and LymphMark assays in December 2019, is reviewed for impairment on an annual basis or more frequently if events or circumstances indicate that it may be impaired. The Company's goodwill evaluation is done annually on October 31 and is based on both qualitative and quantitative assessments regarding the fair value of goodwill relative to its carrying value. The Company has determined that it operates in a single segment and has a single reporting unit associated with the development and commercialization of diagnostic products. In the event the Company determines that it is more likely than not the carrying value of the reporting unit is higher than its fair value, quantitative testing is performed comparing recorded values to estimated fair values. If impairment is present, the impairment loss is measured as the excess of the recorded goodwill over its implied fair value. There was no impairment for the years ended December 31, 2019 , 2018 or 2017 . Fair Value of Financial Instruments The carrying amounts of certain financial instruments including cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. See Note 6, "Fair Value Measurements" for further information on the fair value of the Company’s financial instruments. Revenue Recognition Testing Revenue The Company commenced recognizing testing revenue in accordance with the provisions of ASC 606, Revenue from Contracts with Customers , or ASC 606, starting January 1, 2018. Prior to January 1, 2018, the Company recognized testing revenue in accordance with the provisions of ASC 954-605, Health Care Entities - Revenue Recognition , or ASC 954. Most of the Company’s revenue is generated from the provision of testing services. These services are completed upon the delivery of test results to the prescribing physician, at which time the Company bills for the services. The Company recognizes revenue related to billings based on estimates of the amount that will ultimately be realized. In determining the amount to accrue for a delivered test, the Company considers factors such as payment history, payer coverage, whether there is a reimbursement contract between the payer and the Company, payment as a percentage of agreed upon rate (if applicable), amount paid per test and any current developments or changes that could impact reimbursement. These estimates require significant judgment by management. The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method, which requires a cumulative catch-up adjustment as if the Company had recognized revenue under ASC 606 from January 1, 2016. Prior to January 1, 2018, the Company recognized revenue in accordance with ASC 954 and recognized revenue for tests delivered on an accrual basis when amounts that will ultimately be realized could be reasonably estimated, and on the cash basis when there was insufficient information to estimate revenue accruals. There was sufficient payment history for the Company to substantially accrue all revenue upon delivery of test results starting July 1, 2016 and the Company continued to recognize revenue in 2017 upon cash receipt for unaccrued tests that were delivered prior to July 1, 2016. Testing revenue recognized for the years ended December 31, 2019 , 2018 and 2017 was as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Testing revenue recognized on the accrual basis $ 107,355 100 % $ 91,058 100 % $ 69,274 96 % Testing revenue recognized on the cash basis — — % — — % 2,679 4 % Total $ 107,355 100 % $ 91,058 100 % $ 71,953 100 % As noted above, on July 1, 2016 the Company began recognizing testing revenue from substantially all its tests on the accrual basis of accounting at an amount equal to management’s best estimate of the cash to ultimately be collected. For tests delivered prior to July 1, 2016, substantially all the related cash had been collected by December 31, 2017. Thus, at January 1, 2018, the cumulative impact of adopting ASC 606 was not material and no adjustment was recorded. Since the Company commenced recognizing revenue from substantially all of its tests on the accrual basis of accounting commencing on July 1, 2016, and continued to do so after the adoption of ASC 606, the adoption of ASC 606 did not have a material impact on the Company's statement of operations for the year ended December 31, 2019 . During 2019, the Company changed its testing revenue estimates due to actual and anticipated cash collections for tests delivered in 2018 or prior years and recognized additional revenue of $1.6 million , which resulted in a decrease in the Company's loss from operations of $1.6 million and a decrease in loss per share of $0.04 for the year ended December 31, 2019 . During 2018, the Company changed its testing revenue estimates due to actual and anticipated cash collections for tests delivered in 2017 or prior years and recognized additional revenue of $1.4 million , which resulted in a decrease in the Company's loss from operations of $1.4 million and a decrease in loss per share of $0.04 for the year ended December 31, 2018. Product Revenue The Company began recognizing product revenue in December 2019, when the Company executed an agreement with NanoString for the exclusive global license to the nCounter platform for diagnostic use. More details on this agreement are in Note 4 - Business Combination. Product revenue from instruments, consumables and in vitro diagnostic kits is recognized generally upon shipment or when the instrument is ready for use by the end customer, which is when title of the product has been transferred to the customer. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. Performance obligations are considered satisfied once the Company has transferred control of a product to the customer, meaning the customer has the ability to use and obtain the benefit of the product. The Company recognizes product revenue for satisfied performance obligations only when there are no uncertainties regarding payment terms or transfer of control. Shipping and handling costs incurred for product shipments are charged to the Company's customers and included in product revenue. Revenues are presented net of the taxes that are collected from customers and remitted to governmental authorities. There was no revenue from instrument sales for the years ended December 31, 2019, 2018 or 2017. Biopharmaceutical and Collaboration Revenue From time to time, the Company enters into arrangements for research and development and/or commercialization services. Such arrangements may require the Company to deliver various rights, services and/or samples, including intellectual property rights/licenses, R&D services, and/or commercialization services. The underlying terms of these arrangements generally provide for consideration to the Company in the form of nonrefundable upfront license fees, development and commercial performance milestone payments, royalty payments, and/or profit sharing. In arrangements involving more than one performance obligation, each required performance obligation is evaluated to determine whether it qualifies as a distinct performance obligation based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the arrangement is then allocated to each separate distinct performance obligation based on its respective relative stand-alone selling price. The estimated selling price of each deliverable reflects the Company's best estimate of what the selling price would be if the deliverable was regularly sold by the Company on a stand-alone basis or using an adjusted market assessment approach if selling price on a stand-alone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control of the related goods is transferred or services are performed. Consideration associated with at-risk substantive performance milestones is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Should there be royalties, the Company utilizes the sales and usage-based royalty exception in arrangements that resulted from the license of intellectual property, recognizing revenues generated from royalties or profit sharing as the underlying sales occur. Collaborative Arrangements The Company enters into collaborative arrangements with partners that fall under the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”). While these arrangements are in the scope of ASC 808, the Company may analogize to ASC 606 for some aspects of these arrangements. The Company analogizes to ASC 606 for certain activities within the collaborative arrangement for the delivery of a good or service (i.e., a unit of account) that is part of its ongoing major or central operations. The terms of the Company’s collaborative arrangements typically include one or more of the following: (i) up-front fees; (ii) milestone payments related to the achievement of development, regulatory, or commercial goals; and (iii) royalties on net sales of licensed products. Each of these payments may result in collaboration revenues or an offset against research and development expense. Net sales of data or other services to our customers are classified under biopharmaceutical revenue and collaboration revenue, such as milestones, are classified under collaboration revenue in our consolidated statements of operations and comprehensive loss. As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligations. Generally, the estimation of the stand-alone selling price may include such estimates as independent evidence of market price, forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if they can be satisfied at a point in time or over time, and it measures the services delivered to the collaborative partner which are periodically reviewed based on the progress of the related program. The effect of any change made to an estimated input component and, therefore revenue or expense recognized, would be recorded as a change in estimate. In addition, variable consideration (e.g., milestone payments) must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. Up-front Fees: If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. Milestone Payments: At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or the collaborative partner’s control, such as non-operational developmental and regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or the collaborative partner’s control, such as operational developmental milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment. Services Agreement with Loxo Oncology On April 9, 2018, the Company entered into an agreement with Loxo Oncology, Inc. ("Loxo") whereby the Company agreed to provide certain tissue samples and other services in exchange for agreed-upon fees. During the quarter ended June 30, 2018, the Company recognized $450,000 of revenue upon deliveries of tissue samples and the Company received $500,000 for other services, which was recognized ratably during the quarters ended September 30 and December 31, 2018 as the services were performed. Thereafter, the Company expects to receive approximately $250,000 per quarter as services are performed and may also recognize revenue related to the deliveries of additional tissue samples as long as the agreement is not terminated. The agreement has a one -year term with an automatic renewal of one year and Loxo may terminate the agreement at any time with at least 90 days' notice. As of December 31, 2019, the agreement had not been terminated. The Company evaluated the accounting for this agreement under ASC 606 and concluded that the performance obligations thereunder are the deliveries of tissue samples and performance of services, both of which are distinct. For the year ended December 31, 2019 , the Company recognized revenue of $90,000 for deliveries of tissue samples and $1,000,000 for the performance of services and is classified under biopharmaceutical revenue in the Consolidated Statement of Operations and Comprehensive Loss. There was no deferred revenue related to this agreement at December 31, 2019 . Diagnostic Development Agreement with Johnson & Johnson On December 28, 2018, the Company entered into a diagnostics development agreement with Johnson and Johnson Services, Inc. ("JJSI") (i) to cooperate on a program to enable the Company to use JJSI samples and clinical data to develop a next generation bronchial genomic classifier diagnostic for lung cancer diagnosis (“Percepta v.2") and a nasal genomic classifier diagnostic for lung cancer (“NasaRISK”) and (ii) for JJSI to use Veracyte data generated in two Veracyte development programs for therapeutic purposes and for purposes of developing a companion diagnostic product used in conjunction with a JJSI therapeutic. The Company granted a license to JJSI with the right to use data and under the Company's intellectual property rights for JJSI's therapeutic purposes, including the development and commercialization of a companion diagnostic for its products, from the Percepta v.2 and NasaRISK programs. The license granted to JJSI is not distinct from other performance obligations as JJSI receives benefit only when other performance obligations are met. Under the terms of the agreement, the Company will provide data from its RNA whole-transcriptome sequencing platform to JJSI in exchange for $7.0 million in payments from JJSI. The Company is also entitled to additional payments from JJSI of up to $13.0 million , conditioned upon the achievement of certain milestones relating to the development and reimbursement of Percepta v.2 and NasaRISK. For a period of ten years commencing with the first commercial sale of Percepta v.2 and NasaRISK, respectively, the Company will make payments to JJSI of one percent of net cash collections for Percepta v.2 and in the low-single digits of net cash collections for NasaRISK, depending on the number and timing of JJSI samples and associated clinical data the Company receives from JJSI. The JJSI agreement is considered to be within the scope of ASC 808, as the parties are active participants and exposed to the risks and rewards of the collaborative activity. The Company evaluated the terms of the JJSI agreement and has analogized to ASC 606 for the delivery of data from its RNA whole-transcriptome sequencing platform to JJSI under the collaborative arrangement, which the Company believes is a distinct service for which JJSI meets the definition of a customer. Using the concepts of ASC 606, the Company has identified the delivery of data as its only performance obligation. The Company further determined that the transaction price under the arrangement was the $7.0 million in payments which was allocated to the obligation to deliver data. The $13.0 million in future potential payments is considered variable consideration because the Company determined that the potential payments are contingent upon regulatory and commercialization milestones that are uncertain to occur and, as such, were not included in the transaction price, and will be recognized accordingly as each potential payment becomes probable. The Company recognized revenue of $7.0 million and $4.0 million during 2019 for the provision of data and fulfillment of obligations relating to Percepta v.2 and NasaRISK development milestones, respectively. This revenue is classified under biopharmaceutical revenue and collaboration revenue, respectively, in the consolidated statement of operations and comprehensive loss. Accounts receivable from JJSI was $2.0 million at December 31, 2019 . The cost of biopharmaceutical revenue recognized under the agreement with JJSI is not significant and recorded in research and development in the statement of operations and comprehensive loss. There was no deferred revenue related to this agreement at December 31, 2019 . Collaboration Agreement with AstraZeneca Group On December 23, 2019, the Company entered into an agreement with Acerta Pharma B.V. ("Acerta"), a member of AstraZeneca Group whereby the Company agreed to provide genomic information that will support Acerta’s development of oncology therapeutics. Acerta will reimburse the Company for certain development costs and pay milestones to the Company for the achievement of development milestones. As of December 31, 2019, there was no performance of obligations under the agreement or consideration paid. The agreement will be accounted for in accordance with the policy on collaborative arrangements, as mentioned in this footnote. Cost of Testing Revenue The components of our cost of testing services are laboratory expenses, sample collection expenses, compensation expense, license fees and royalties, depreciation and amortization, other expenses such as equipment and laboratory supplies, and allocations of facility and information technology expenses. Costs associated with performing tests are expensed as the test is processed regardless of whether and when revenue is recognized with respect to that test. Cost of Product Revenue Cost of product revenue consists primarily of costs of purchasing instruments and consumables from third-party contract manufacturers, installation, warranty, service and packaging and delivery costs. In addition, cost of product includes royalty costs for licensed technologies included in the Company’s products and labor expenses. Cost of product revenue for instruments and consumables is recognized in the period the related revenue is recognized. Shipping and handling costs incurred for product shipments are included in cost of product in the consolidated statements of operations. Research and Development Research and development expenses include expenses incurred to develop our technology, collect clinical samples and conduct clinical studies to develop and support our products. These expenses consist of compensation expenses, direct research and development expenses such as prototype materials, laboratory supplies and costs associated with setting up and conducting clinical studies at domestic and international sites, professional fees, depreciation and amortization, other miscellaneous expenses and allocation of facility and information technology expenses. We expense all research and development costs in the periods in which they are incurred. Income Taxes The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. The Company's assessment of an uncertain tax position begins with the initial determination of the position's sustainability and is measured at the largest amount of benefit that is more-likely-than-not of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the

Net Loss Per Share

Net Loss Per Share	12 Months Ended
Net Loss Per Share	Dec. 31, 2019
Earnings Per Share [Abstract]
Net Loss Per Share	Net Loss Per Share The following outstanding common stock equivalents have been excluded from diluted net loss per common share for the years ended December 31, 2019 , 2018 and 2017 because their inclusion would be anti-dilutive: Year Ended December 31, 2019 2018 2017 Shares of common stock subject to outstanding options 5,394,944 5,998,163 6,163,734 Employee stock purchase plan 26,124 34,869 34,559 Restricted stock units 712,122 384,691 63,425 Total common stock equivalents 6,133,190 6,417,723 6,261,718

Business Combination

Business Combination	12 Months Ended
Business Combination	Dec. 31, 2019
Business Combinations [Abstract]
Business Combination	Business Combination Exclusive License to NanoString Diagnostics Platform On December 3, 2019, the Company executed an agreement with NanoString for the exclusive global diagnostics license to the nCounter FLEX Analysis System, the Prosigna breast cancer prognostic gene signature assay, and the LymphMark lymphoma subtyping assay. The strategic transaction positions the Company to expand its genomic diagnostics business globally, with the ability to deliver its advanced genomic tests to physicians and their patients via hospital and clinical laboratories throughout the European Union and other parts of the world. The Company has accounted for this agreement under Accounting Standards Codification 805, Business Combinations . Pursuant to the terms of the agreement, Veracyte paid NanoString $40.0 million in cash and $10.0 million in Veracyte common stock, and may pay up to an additional $10.0 million in cash, contingent upon the commercial launch of Veracyte diagnostic tests for use on the platform. This contingency was valued at $6.1 million as of the acquisition date, recorded as a liability, and will be remeasured to fair value at each reporting date until the contingent consideration is settled. Assets acquired are recorded based on valuations derived from estimated fair value assessments and assumptions used by the Company. While the Company believes that its estimates and assumptions underlying the valuations are reasonable, different estimates and assumptions could result in different valuations assigned to the individual assets acquired and the resulting amount of goodwill. The following table summarizes the fair values of assets acquired and liabilities assumed at the date of acquisition (in thousands): Prosigna product technology $ 4,120 Prosigna customer relationships 2,430 nCounter FLEX Dx license 46,880 LymphMark product technology 990 Total identifiable intangible assets acquired 54,420 Goodwill 1,668 Net assets acquired $ 56,088 Identifiable acquisition-related intangibles included in the above table are finite-lived and are being amortized on a straight-line basis over their estimated lives, which approximates the pattern in which the economic benefits of the intangible assets are expected to be realized, as follows: Estimated Useful life (In Years) Prosigna product technology 15 Prosigna customer relationships 5 nCounter FLEX Dx license 15 LymphMark product technology 7 Goodwill represents the excess of the purchase price over the fair value of the net tangible and intangible assets acquired. This acquisition includes $1.7 million of goodwill which the Company believes consists principally of the organized workforce that will help the Company execute its strategic plans in relation to the assets acquired. In accordance with ASC 350, goodwill will not be amortized but will be tested for impairment at least annually. As of December 31, 2019, goodwill is not deductible for tax purposes, however, if contingent consideration is paid at a future date, the portions of contingent consideration paid and allocated to the intangible assets for tax purposes will be tax deductible. The accounting for this acquisition is preliminary and will be finalized upon completion of the analysis of certain contracts acquired and executed as part of this acquisition along with the impact on goodwill, should there be any. The unaudited pro forma financial information in the table below summarizes the combined revenue for the Company and acquired business from NanoString as though the acquisition had been executed as of January 1, 2018. The pro forma amounts have been adjusted in the table below. NanoString’s historical books and records did not contain the operating expense information to prepare the financial disclosures required in the pro forma table below. Thus, the pro forma financial disclosures are limited to revenue only. The unaudited pro forma revenue information is for informational purposes only and is not necessarily indicative of the revenue that would have been achieved if the acquisition had taken place as of January 1, 2018 (in thousands): Year Ended December 31, 2019 2018 Product revenue $ 11,040 $ 11,482

Balance Sheet Components

Balance Sheet Components	12 Months Ended
Balance Sheet Components	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Components	Balance Sheet Components Property and Equipment, Net Property and equipment consisted of the following (in thousands of dollars): December 31, 2019 2018 Leasehold improvements $ 5,926 $ 5,825 Laboratory equipment 9,655 8,895 Computer equipment 1,709 1,615 Software, including software developed for internal use 3,226 2,450 Furniture and fixtures 1,482 1,435 Construction-in-process 1,015 726 Total property and equipment, at cost 23,013 20,946 Accumulated depreciation and amortization (14,080 ) (12,006 ) Total property and equipment, net $ 8,933 $ 8,940 Depreciation and amortization expense was $2.7 million , $2.9 million and $2.8 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. The Company had a capital lease for laboratory equipment that went into service in 2017. The lease was paid off in 2019 and the cost of $1.2 million was included in Property and Equipment as of December 31, 2019. The laboratory equipment had accumulated depreciation of $600,000 and $367,000 at December 31, 2019 and 2018 , respectively and depreciation of $233,000 , $232,000 , and $135,000 for the years ended December 31, 2019 , 2018 and 2017, respectively. Finite-lived Intangible Assets, Net Finite-live intangible assets consisted of the following (in thousands of dollars): December 31, 2019 December 31, 2018 Weighted Average Amortization Period (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Percepta product technology $ 16,000 $ (5,067 ) $ 10,933 $ 16,000 $ (4,000 ) $ 12,000 15 Prosigna product technology 4,120 (17 ) 4,103 — — — 15 Prosigna customer relationships 2,430 (42 ) 2,388 — — — 5 nCounter FLEX Dx license 46,880 (263 ) 46,617 — — — 15 LymphMark product technology 990 (12 ) 978 — — — 7 Total $ 70,420 $ (5,401 ) $ 65,019 $ 16,000 $ (4,000 ) $ 12,000 14.5 Amortization of the Percepta product technology, which was acquired from the acquisition of Allegro in September 2014, began in April 2015 when research and development activities were deemed to be completed and is recognized on a straight-line basis. Amortization of the Prosigna product technology, Prosigna customer relationships, nCounter FLEX Dx license and LymphMark product technology, which were acquired under an agreement with NanoString, see Note 4 - Business Combination, began in December 2019 and is recognized on a straight-line basis. Amortization of $1.4 million , $1.1 million and $1.1 million was recognized for the years ended December 31, 2019 , 2018 , and 2017 , respectively. The estimated future aggregate amortization expense as of December 31, 2019 is as follows (in thousands of dollars): Year Ending December 31, Amounts 2020 $ 5,095 2021 5,094 2022 5,094 2023 5,094 2024 5,054 Thereafter 39,588 Total $ 65,019 Accrued Liabilities Accrued liabilities consisted of the following (in thousands of dollars): December 31, 2019 2018 Accrued compensation expense $ 10,100 $ 6,412 Accrued other 3,634 2,774 Total accrued liabilities $ 13,734 $ 9,186

Fair Value Measurements

Fair Value Measurements	12 Months Ended
Fair Value Measurements	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company records its financial assets and liabilities at fair value. The carrying amounts of certain financial instruments of the Company, including cash and cash equivalents, prepaid expenses and other current assets, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities. The carrying value of the Company's debt approximates its fair value because the interest rate approximates market rates that the Company could obtain for debt with similar terms. The fair value of the Company’s debt is estimated using the net present value of the payments, discounted at an interest rate that is consistent with market interest rates, which is a Level II input. The accounting guidance for fair value provides a framework for measuring fair value, clarifies the definition of fair value, and expands disclosures regarding fair value measurements. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: • Level I: Inputs which include quoted prices in active markets for identical assets and liabilities; • Level II: Inputs other than Level I that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities; and • Level III: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The fair value of the Company's financial assets includes money market funds, overnight reverse repurchase agreements and a deposit for the lease of the Company's South San Francisco facility. Money market funds, included in cash and cash equivalents in the accompanying consolidated balance sheets, was $57.6 million and $76.6 million as of December 31, 2019 and 2018 , respectively, and are Level I assets as described above. Overnight reverse repurchase agreements, included in cash and cash equivalents in the accompanying consolidated balance sheets, were $100.0 million and zero as of December 31, 2019 and 2018, respectively, and are Level II assets as described above. There were no unrealized gains or losses from overnight reverse repurchase agreements at December 31, 2019 and 2018. The deposit for the lease, included in restricted cash in the accompanying consolidated balance sheets, was $603,000 as of December 31, 2019 and 2018 , and is a Level I asset as described above. The contingent consideration in Note 4, Business Combination, associated with the agreement with NanoString on December 3, 2019, is a Level III financial liability. As of December 31, 2019, the contingent consideration of $6.1 million is dependent on the achievement of certain milestones and is payable in cash of up to $10.0 million . Estimation of the fair value of the contingent consideration is based on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying value of the contingent consideration that are not readily apparent from other sources. Actual results could differ from those estimates and assumptions. Changes to the forecasts for the achievement of milestones can significantly affect the estimated fair value of the contingent consideration. There has been no change to the estimated fair value of the contingent consideration from the date of the agreement with NanoString to December 31, 2019 and the Company will assess the fair value of the contingent liability on a quarterly basis.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases The Company leases its headquarters and laboratory facilities in South San Francisco, California under a non-cancelable lease agreement for approximately 59,000 square feet. The lease began in June 2015 and ends in March 2026 and contains extension of lease term and expansion options. In February 2017, the Company relinquished certain expansion rights for a nominal fee. The Company had deposits of $603,000 included in long-term assets as of December 31, 2019 and 2018 , restricted from withdrawal and held by a bank in the form of collateral for an irrevocable standby letter of credit held as security for the lease of the South San Francisco facility. The Company also leases laboratory and office space in Austin, Texas under a lease that expires in January 2029 and includes options for expansion and early termination in 2025. The Company provided a cash security deposit for this lease of $139,000 , included in other assets in the Company's balance sheets as of December 31, 2019 and 2018 . The Company determined its operating lease liabilities for the two operating leases mentioned above using a discount rate of 7.53% based on the rate that the Company would have to pay to borrow on a collateralized basis for a similar lease an amount equal to the lease payments in a similar economic environment. Operating lease liabilities along with the associated right-of-use assets as of December 31, 2019 are disclosed in the accompanying consolidated balance sheets. After the adoption of ASC 842, the Company classified its deferred rent for tenant improvements with its operating lease right-of-use assets on the consolidated balance sheets. Future minimum lease payments under non-cancelable operating leases as of December 31, 2019 are as follows (in thousands of dollars): Year Ending December 31, Amounts 2020 $ 2,332 2021 2,401 2022 2,472 2023 2,543 2024 2,614 Thereafter 4,226 Total future minimum lease payments 16,588 Less: amount representing interest 3,675 Present value of future lease payments 12,913 Less: short-term lease liabilities 1,407 Long-term lease liabilities $ 11,506 The Company recognizes rent expense on a straight-line basis over the non-cancelable lease period. Rent expense was $1.9 million , $1.9 million , and $1.9 million for the years ended December 31, 2019 , 2018 and 2017 , respectively. Supplies Purchase Commitments The Company had non-cancelable purchase commitments with suppliers to purchase a minimum quantity of supplies for approximately $7.6 million at December 31, 2019 . Contingencies

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2019
Debt Disclosure [Abstract]
Debt	Debt Loan and Security Agreement On November 3, 2017, the Company entered into a loan and security agreement (the “Loan and Security Agreement”) with Silicon Valley Bank. The Loan and Security Agreement allows the Company to borrow up to $35.0 million , with a $25.0 million advance term loan (the “Term Loan Advance”) and a revolving line of credit of up to $10.0 million (the “Revolving Line of Credit”). The Term Loan Advance was advanced upon the closing of the Loan and Security Agreement and was used to pay the outstanding balance of the Company’s existing long-term debt, which was canceled at that date. The Company had not drawn on the Revolving Line of Credit as of December 31, 2019. Borrowings under the Loan and Security Agreement mature on October 1, 2022. Amounts may be borrowed and repaid under the Revolving Line of Credit up until the earliest of full repayment or maturity of the Loan and Security Agreement, termination of the Loan and Security Agreement, or October 1, 2022. The Term Loan Advance bears interest at a variable rate equal to (i) the thirty-day U.S. London Interbank Offer Rate (“LIBOR”) plus (ii) 4.20% , with a minimum rate of 5.43% per annum. Principal amounts outstanding under the Revolving Line of Credit bear interest at a variable rate equal to (i) LIBOR plus (ii) 3.50% , with a minimum rate of 4.70% per annum. The average Term Loan Advance interest rate for the year ended December 31, 2019 was 6.70% . The Company may prepay the outstanding principal amount under the Term Loan Advance plus accrued and unpaid interest and, if the Term Loan Advance is repaid in full, a prepayment premium. The prepayment premium will be (i) $750,000 if prepayment is made prior to November 3, 2018, (ii) $500,000 if the prepayment is made after November 3, 2018 but on or before November 3, 2019, or (iii) $250,000 if the prepayment is made after November 3, 2019. In January 2019 and May 2019, the Company prepaid $12.5 million and $12.4 million , respectively, of the principal amount of the Term Loan Advance. These prepayments did not trigger any prepayment premium because they were partial, not full, repayments of the principal amount. In addition, a final payment on the Term Loan Advance in the amount of $1.2 million is due upon the earlier of the maturity date of the Term Loan Advance or its payment in full. The Loan and Security Agreement contains customary representations, warranties, and events of default such as a material adverse change in our business, operations or financial condition, as well as affirmative and negative covenants. The negative covenants include, among other provisions, covenants that limit or restrict the Company's ability to incur liens, make investments, incur indebtedness, merge with or acquire other entities, dispose of assets, make dividends or other distributions to holders of its equity interests, engage in any new line of business, or enter into certain transactions with affiliates, in each case subject to certain exceptions. The Company’s obligations under the Loan and Security Agreement are secured by substantially all of its assets (excluding intellectual property), subject to certain customary exceptions. The Loan and Security Agreement also requires the Company to achieve certain revenue levels tested quarterly on a trailing twelve-month basis. However, failure to maintain the revenue levels will not be considered a default if the Company maintains liquidity of at least $40.0 million . As of December 31, 2019 , the Company was in compliance with the loan covenants. As of December 31, 2019 and 2018 , the net debt obligation for borrowings made under the Loan and Security Agreement was as follows (in thousands of dollars): December 31, 2019 2018 Debt principal $ 100 $ 25,000 End-of-term debt obligation 594 365 Unamortized debt issuance costs — (83 ) Net debt obligation $ 694 $ 25,282 Future principal and end-of-term debt obligation payments due under the Loan and Security Agreement are $1.3 million in 2022. The end-of-term debt obligation accretes over the term of the Loan and Security Agreement until maturity and is included in interest expense in the Company's consolidated statement of operations and comprehensive loss. Credit Agreement In March 2016, the Company entered into a credit agreement (the “Credit Agreement”) with Visium Healthcare Partners, LP (“Visium”). Under the Credit Agreement, two term loans were available to the Company with an aggregate principal amount of up to $40.0 million . The Company drew down the initial $25.0 million term loan (the “Initial Term Loan”) on March 30, 2016, of which $5.0 million was used to pay the outstanding balance of the Company’s previous long-term debt, which was canceled at that date. The Term Loans bore interest at a fixed rate of 12.0% per annum and no principal payments were due through March 31, 2020. The Company was obligated to repay the outstanding principal amounts under the Term Loans in eight equal installments during the final two years under the Credit Agreement. Prepayment of the outstanding principal amount under the Term Loans prior to March 31, 2018 was subject to a prepayment premium equal to 24.0% of the outstanding principal balance, less the aggregate amount of all interest payments in cash. For any quarterly interest payment through and including the 16th interest payment date after the Initial Borrowing Date, so long as no event of default had occurred and was then continuing, the Company could have elected to pay interest in cash on the outstanding principal amounts of the Term Loans at a fixed rate of 9.0% , with the remaining 3.0% of the 12.0% interest paid-in-kind by adding such paid-in-kind interest to the outstanding principal amounts of the Term Loans. The Company elected to pay interest in-kind for the quarters ended June 30, 2016 and September 30, 2016, totaling $385,000 . As noted above, upon entering into the Loan and Security Agreement, the Credit Agreement was paid in full and terminated on November 3, 2017, wherein all commitments were terminated, all liens were released and all outstanding principal, interest and fees accrued thereunder were repaid in the aggregate amount of $27.3 million , including a prepayment premium of $1.5 million . Interest Expense Interest expense was recognized as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Nominal debt interest $ 332 $ 1,568 $ 2,838 Amortization and write-off of debt discount and issuance costs 107 57 472 End-of-term debt obligation interest 229 312 53 Debt prepayment penalty — — 1,536 Interest on capital lease 9 26 42 Total $ 677 $ 1,963 $ 4,941

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2019
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Common Stock The Company's Restated Certificate of Incorporation authorizes the Company to issue 125,000,000 shares of common stock with a par value of $0.001 per share. The holder of each share of common stock shall have one vote for each share of stock. The common stockholders are also entitled to receive dividends whenever funds and assets are legally available and when declared by the Board of Directors, subject to the prior rights of holders of all series of convertible preferred stock outstanding. No dividends have been declared as of December 31, 2019 . As of December 31, 2019 and 2018 , the Company had reserved shares of common stock for issuance as follows: December 31, 2019 2018 Stock options and restricted stock units issued and outstanding 5,562,484 6,235,258 Stock options and restricted stock units available for grant under stock option plans 1,954,804 1,571,658 Common stock available for the Employee Stock Purchase Plan 173,168 309,419 Total 7,690,456 8,116,335 On May 7, 2019, the Company issued and sold 6,325,000 shares of common stock in a registered public offering, including 825,000 shares issued and sold upon the underwriters’ exercise in full of their option to purchase additional shares, at a price to the public of $23.25 per share. The Company's net proceeds from the offering were approximately $137.8 million , after deducting underwriting discounts and commissions and offering expenses of $9.2 million . In July 2018, the Company issued and sold 5,750,000 shares of common stock in a registered public offering, including 750,000 shares issued and sold upon the underwriters' exercise in full of their option to purchase additional shares, at a price to the public of $10.25 per share. The Company's net proceeds from the offering were $55.0 million , after deducting underwriting commissions and offering expenses of $3.9 million .

Stock Incentive Plans

Stock Incentive Plans	12 Months Ended
Stock Incentive Plans	Dec. 31, 2019
Share-based Payment Arrangement [Abstract]
Stock Incentive Plans	Stock Incentive Plans Stock Plans In February 2008, the Company adopted the 2008 Stock Plan (the "2008 Plan"). The 2008 Plan provides for the granting of options to purchase common stock and common stock to employees, directors and consultants of the Company. The Company may grant incentive stock options ("ISOs"), non-statutory stock options ("NSOs") or restricted stock under the 2008 Plan. ISOs may only be granted to Company employees (including directors who are also considered employees). NSOs and restricted stock may be granted to Company employees, directors and consultants. Options may be granted for terms of up to ten years from the date of grant, as determined by the Board of Directors, provided however, that with respect to an ISO granted to a person who owns stock representing more than 10% of the voting power of all classes of stock of the Company, the term shall be for no more than five years from the date of grant. The exercise price of options granted must be at a price no less than 100% of the estimated fair value of the shares on the date of grant, as determined by the Board of Directors, provided however, that with respect to an ISO granted to an employee who at the time of grant of such option owns stock representing more than 10% of the voting power of all classes of stock of the Company, the exercise price shall not be less than 110% of the estimated fair value of the shares on the date of grant. In October 2013, the Company adopted the 2013 Stock Incentive Plan (the "2013 Plan"). The 2013 Plan was subsequently approved by the Company's stockholders and became effective on November 4, 2013, immediately before the closing of the Company's initial public offering ("IPO"). Following the effectiveness of the 2013 Plan, no additional options were granted under the 2008 Plan. An aggregate of 1,700,000 shares were initially reserved for issuance under the 2013 Plan. In addition, to the extent that any awards outstanding or subject to vesting restrictions under the 2008 Plan are subsequently forfeited or terminated for any reason before being exercised or settled, the shares of common stock reserved for issuance pursuant to such awards as of the closing of the IPO will become available for issuance under the 2013 Plan. The remaining shares available for grant under the 2008 Plan became available for issuance under the 2013 Plan upon the closing of the IPO. On the first day of each year from 2014 to 2023, the 2013 Plan authorizes an annual increase of the lesser of 4% of outstanding shares on the last day of the immediately preceding fiscal year or a lesser amount as determined by the Company's Board of Directors. As of December 31, 2019 , 1,954,799 shares were available for future issuance under the 2013 Plan. Pursuant to the 2013 Plan, stock options, restricted shares, stock units, including restricted stock units and stock appreciation rights may be granted to employees, consultants, and outside directors of the Company. Options granted may be either ISOs or NSOs. Stock options are governed by stock option agreements between the Company and recipients of stock options. ISOs and NSOs may be granted under the 2013 Plan at an exercise price of not less than 100% of the fair market value of the common stock on the date of grant, determined by the Compensation Committee of the Board of Directors. Options become exercisable and expire as determined by the Compensation Committee, provided that the term of ISOs may not exceed ten years from the date of grant. Stock option agreements may provide for accelerated exercisability in the event of an optionee's death, disability, or retirement or other events. Stock units are governed by stock unit agreements between the Company and recipients of stock units. Stock units may be granted under the 2013 Plan and the number of stock units awarded are determined by the Compensation Committee of the Board of Directors. Stock units vest and expire as determined by the Compensation Committee. Stock unit agreements may provide for accelerated vesting in the event of a stock unit holder's death, disability, or retirement or other events. Any outside director who was not previously an employee and who first joins the Company's Board of Directors on or after the effective date of the 2013 Plan will be automatically granted an initial NSO to purchase 35,000 shares of common stock upon first becoming a member of the Board of Directors. The shares subject to the initial option will vest and become exercisable one-third (1/3) each of the first, second and third annual anniversaries of the date of grant. On the first business day after each regularly scheduled annual meeting of stockholders, each outside director who was not elected to the Board of Directors for the first time at such meeting and who will continue serving as a member of the Board of Directors thereafter will be automatically granted an option to purchase 10,000 shares of common stock, provided that the outside director has served on the Board of Directors for at least six months . Each annual option will vest and become exercisable on the first anniversary of the date of grant, or immediately prior to the next regular annual meeting of the Company's stockholders following the date of grant if the meeting occurs prior to the first anniversary date. The options granted to outside directors will have a per share exercise price equal to 100% of the fair market value of the underlying shares on the date of grant and will become fully vested in the event of a change of control. In addition, such options will terminate on the earlier of (i) the day before the 10 th anniversary of the date of grant or (ii) the date 12 months after the termination of the outside director's service for any reason. The following table summarizes activity under the Company's stock incentive plans (aggregate intrinsic value in thousands): Shares Available for Grant Stock Options Weighted Weighted Average Aggregate Balance—December 31, 2018 1,571,658 6,235,258 $ 7.95 6.95 $ 27,340 Additional shares authorized 1,634,528 — Granted - stock options (969,500 ) 969,500 21.16 Granted - restricted stock units (505,965 ) 505,965 Canceled 180,017 (180,017 ) 9.40 Exercised — (1,846,222 ) 7.77 Restricted stock units vested — (122,000 ) Tax portion of restricted stock units vested 44,066 — Balance—December 31, 2019 1,954,804 5,562,484 $ 10.66 6.97 $ 79,760 Options vested and exercisable—December 31, 2019 2,651,858 $ 8.13 5.90 $ 52,469 Options vested and expected to vest—December 31, 2019 4,442,275 $ 10.48 6.91 $ 77,453 The aggregate intrinsic value was calculated as the difference between the exercise price of the options to purchase common stock and the fair market value of the Company's common stock, which was $27.92 and $12.58 per share as of December 31, 2019 and 2018, respectively. The weighted average fair value of options to purchase common stock granted was $11.07 , $3.62 and $4.49 for the years ended December 31, 2019, 2018 and 2017, respectively. The aggregate estimated grant date fair value of employee options to purchase common stock vested during the years ended December 31, 2019, 2018 and 2017 was $4.4 million , $4.1 million and $3.1 million , respectively. The intrinsic value of stock options exercised was $31.3 million , $4.9 million and $0.7 million for the years ended December 31, 2019, 2018 and 2017, respectively. The weighted average fair value of restricted stock units granted was $21.90 and $6.17 for the years ended December 31, 2019 and 2018, respectively. The intrinsic value of restricted stock units vested was $2,720,000 and $184,000 for the years ended December 31, 2019 and 2018, respectively. Employee Stock Purchase Plan In May 2015, the Company's stockholders approved the Company's ESPP. The ESPP provides eligible employees with an opportunity to purchase common stock from the Company and to pay for their purchases through payroll deductions. The ESPP will be implemented through a series of offerings of purchase rights to eligible employees. Under the ESPP, the Compensation Committee of the Company's Board of Directors may specify offerings with a duration of not more than 12 months , and may specify shorter purchase periods within each offering. During each purchase period, payroll deductions will accumulate, without interest. On the last day of the purchase period, accumulated payroll deductions will be used to purchase common stock for employees participating in the offering. The purchase price will be specified pursuant to the offering, but cannot, under the terms of the ESPP, be less than 85% of the fair market value per share of the Company's common stock on either the offering date or on the purchase date, whichever is less. The Company's Board of Directors has determined that the purchase periods initially shall have a duration of six months , that the first purchase period began on August 3, 2015 and that the purchase price will be 85% of the fair market value per share of the Company's common stock on either the offering date or the purchase date, whichever is less. The length of the purchase period applicable to U.S. employees and the purchase price may not be changed without the approval of the independent members of the Compensation Committee of the Company's Board of Directors. The Compensation Committee has determined that if the fair market value of a share of the Company's common stock on any purchase date within a particular offering period is less than the fair market value on the start date of that offering period, then the offering period will automatically terminate and the employees in that offering period will automatically be transferred and enrolled in a new offering period which will begin on the next day following such purchase date. No employee is permitted to accrue, under the ESPP, a right to purchase stock of the Company having a value in excess of $25,000 of the fair market value of such stock (determined at the time the right is granted) for each calendar year. Stock-based Compensation The following table summarizes stock-based compensation expense related to stock options, restricted stock units and the ESPP for the years ended December 31, 2019, 2018 and 2017, and are included in the consolidated statements of operations and comprehensive loss as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Cost of testing revenue $ 277 $ 130 $ 133 Research and development 1,856 1,018 1,495 Selling and marketing 2,938 1,866 1,899 General and administrative 4,736 2,944 3,090 Total stock-based compensation expense $ 9,807 $ 5,958 $ 6,617 As of December 31, 2019, the Company had $18.4 million of unrecognized compensation expense related to unvested stock options and restricted stock units, which is expected to be recognized over an estimated weighted-average period of 2.20 years . The estimated grant-date fair value of employee stock options was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility 52.90 - 53.40% 50.40 - 52.70% 50.40 - 52.40% Weighted-average expected term (years) 5.50 - 6.08 5.50 - 6.08 5.50 - 6.08 Risk-free interest rate 1.90 - 2.60% 2.40 - 3.10% 1.80 - 2.33% Expected dividend yield — — — The estimated fair value of non-employee stock options was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility —% 43.60 - 50.50% 50.40 - 51.10% Weighted-average expected term (years) — 0.25 - 6.75 6.80 - 7.75 Risk-free interest rate —% 1.84 - 2.87% 2.16 - 2.37% Expected dividend yield — — — There were no non-employee stock options outstanding as of December 31, 2019. The estimated grant date fair value of the ESPP shares was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility 53.38 - 71.77% 42.88 - 47.74% 37.00 - 43.86% Weighted-average expected term (years) 0.50 - 1.00 0.50 - 1.00 0.50 - 1.00 Risk-free interest rate 1.88 - 2.56% 1.64 - 2.45% 0.65 - 1.22% Expected dividend yield — — —

Thyroid Cytopathology Partners

Thyroid Cytopathology Partners	12 Months Ended
Thyroid Cytopathology Partners	Dec. 31, 2019
Thyroid Cytopathology Partners
Thyroid Cytopathology Partners	Thyroid Cytopathology Partners The Company has an agreement with a specialized pathology practice, Thyroid Cytopathology Partners, ("TCP"), to provide testing services to the Company (the "TCP Agreement"). The TCP Agreement is effective through October 31, 2022, and thereafter automatically renews every year unless either party provides notice of intent not to renew at least 12 months prior to the end of the then-current term. Under the TCP Agreement, the Company pays TCP based on a fixed price per test schedule which is reviewed periodically for changes in market pricing, and the TCP Agreement included a clause allowing TCP to sublease a portion of the Company's facility in Austin, Texas. The Company does not have an ownership interest in or provide any form of financial or other support to TCP. The Company previously concluded that TCP represented a variable interest entity as a result of the facility arrangement clause, but that the Company was not the primary beneficiary as it did not have the ability to direct the activities that most significantly impacted TCP's economic performance, and therefore did not consolidate TCP. On February 14, 2019, the TCP Agreement was amended to remove the facility clause. Accordingly, the Company believes TCP was no longer a variable interest entity as of that date. TCP's portion of rent and related operating expenses reimbursed to the Company for the shared space at the Austin, Texas facility was $11,000 , $128,000 and $114,000 for the years ended December 31, 2019 , 2018 and 2017 and is included other income, net in the Company's consolidated statements of operations and comprehensive loss.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company generated a pretax loss of $12.5 million , $23.0 million and $31.0 million in the United States for the years ended December 31, 2019 , 2018 and 2017 , respectively. Since inception, the Company has not generated any pretax income or loss outside of the United States. The Company recorded no provision for income taxes during the years ended December 31, 2019 , 2018 or 2017 . The Company follows FASB ASC No. 740, Income Taxes for the Computation and Presentation of its Tax Provision. The following table presents a reconciliation of the income tax expense computed at the statutory federal rate and the Company's income tax expense for the periods presented (in thousands of dollars): Year Ended December, 31, 2019 2018 2017 U.S. federal taxes at statutory rate $ (2,632 ) $ (4,825 ) $ (10,541 ) State tax (net of federal benefit) (828 ) — 15 Non deductible officers' compensation 439 409 — Stock based compensation - PSU/RSU/NQSQ 628 — — Permanent differences 221 285 198 Incentive stock options (4,994 ) (256 ) 994 Tax credits (996 ) (777 ) (588 ) Change in valuation allowance 8,162 5,164 (14,552 ) Rate differential impact - Tax Cuts and Jobs Act — — 24,474 Total $ — $ — $ — Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. Significant components of the Company's deferred tax assets and liabilities are as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 56,506 $ 50,410 $ 47,177 Research and development credits 5,579 4,584 4,034 Stock-based compensation 2,246 1,032 2,068 NanoString intangibles and goodwill 380 — — Operating lease liability 3,068 — — Accruals and other 2,610 2,918 2,375 Gross deferred tax assets 70,389 58,944 55,654 Valuation allowance (65,228 ) (55,366 ) (51,657 ) Net deferred tax assets 5,161 3,578 3,997 Deferred tax liabilities: Property and equipment (471 ) (695 ) (983 ) In-process research and development (2,597 ) (2,883 ) (3,014 ) ROU assets (2,093 ) — — Gross deferred tax liabilities (5,161 ) (3,578 ) (3,997 ) Net deferred tax liabilities (5,161 ) (3,578 ) (3,997 ) Net deferred taxes $ — $ — $ — The Company has established a full valuation allowance against its net deferred tax assets due to the uncertainty surrounding realization of such assets. The valuation allowance increased $9.9 million during the year ended December 31, 2019 , increased $3.7 million during the year ended December 31, 2018 and decreased $14.3 million during the year ended December 31, 2017 . As of December 31, 2019 , the Company had net operating loss carryforwards of approximately $236.9 million , $58.3 million and $45.2 million available to reduce future taxable income, if any, for federal, California and other state income tax purposes, respectively. The U.S. federal net operating loss carryforwards will begin to expire in 2026 while for state purposes, the net operating losses began to expire in 2028. As of December 31, 2019 , the Company had net research and development credit carryforwards of approximately $4.9 million and $4.7 million available to reduce future taxable income, if any, for federal and state income tax purposes, respectively. The federal credit carryforwards begin to expire in 2028 . California credits have no expiration date. Other state credit carryforwards begin to expire in 2023 . The Internal Revenue Code of 1986, as amended, imposes restrictions on the utilization of net operating losses and tax credits in the event of an "ownership change" of a corporation. Accordingly, a company's ability to use net operating losses and tax credits may be limited as prescribed under Internal Revenue Code Section 382 and 383 ("IRC Section 382"). Events which may cause limitations in the amount of the net operating losses or tax credits that the Company may use in any one year include, but are not limited to, a cumulative ownership change of more than 50% over a three-year period. Utilization of the federal and state net operating losses may be subject to substantial annual limitation due to the ownership change limitations provided by the IRC Section 382 rules and similar state provisions. In the event the Company has any changes in ownership, net operating losses and research and development credit carryovers could be limited and may expire unutilized. Uncertain Tax Positions As of December 31, 2019 , the Company had unrecognized tax benefits of $3.3 million , none of which would currently affect the Company's effective tax rate if recognized due to the Company's deferred tax assets being fully offset by a valuation allowance. The Company does not anticipate that the amount of unrecognized tax benefits relating to tax positions existing at December 31, 2019 will significantly increase or decrease within the next 12 months. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Unrecognized tax benefits, beginning of period $ 2,799 $ 2,523 $ 2,222 Gross increases—tax position in prior period — — — Gross decreases—tax position in prior period — (97 ) — Gross increases—current period tax position 479 373 301 Lapse of statute of limitations — — — Unrecognized tax benefits, end of period $ 3,278 $ 2,799 $ 2,523 It is the Company's policy to include penalties and interest expense related to income taxes as a component of other income (expense), net, and interest expense, respectively, as necessary. There was no interest expense or penalties related to unrecognized tax benefits recorded through December 31, 2019 . The Company's major tax jurisdictions are the United States and California. All of the Company's tax years will remain open for examination by the Federal and state tax authorities for three and four years , respectively, from the date of utilization of the net operating loss or research and development credit. The Company does not have any tax audits pending.

401(k) Plan

401(k) Plan	12 Months Ended
401(k) Plan	Dec. 31, 2019
Retirement Benefits [Abstract]
401(k) Plan	401(k) Plan The Company sponsors a 401(k) defined contribution plan covering all employees. Employer contributions to the plan were $509,000 , $448,000 and $324,000 for the years ended December 31, 2019 , 2018 , and 2017

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
Selected Quarterly Financial Data (Unaudited)	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) The following table presents selected unaudited financial data for each of the eight quarters in the two-year period ended December 31, 2019 . The Company believes this information reflects all recurring adjustments necessary to fairly present this information when read in conjunction with the Company's financial statements and the related notes. Net loss per common share, basic and diluted, for the four quarters of each fiscal year may not sum to the total for the fiscal year because of the different number of shares outstanding during each period. The results of operations for any quarter are not necessarily indicative of the results to be expected for any future period (in thousands of dollars, except for share and per share data): Quarter Ended March 31 June 30 September 30 December 31 2019: Revenue $ 29,529 $ 30,136 $ 30,973 $ 29,730 Net loss (1,917 ) (2,494 ) (730 ) (7,458 ) Net loss per common share, basic and diluted (0.05 ) (0.05 ) (0.02 ) (0.15 ) Shares used to compute net loss per common share, basic and diluted 41,168,593 45,586,081 48,588,296 49,095,703 2018: Revenue $ 20,041 $ 22,751 $ 23,466 $ 25,750 Net loss (9,177 ) (6,248 ) (4,469 ) (3,105 ) Net loss per common share, basic and diluted (0.27 ) (0.18 ) (0.12 ) (0.08 ) Shares used to compute net loss per common share, basic and diluted 34,271,254 34,314,234 38,620,036 40,731,334

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2019
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Significant items subject to such estimates include: revenue recognition; the useful lives of property and equipment; the recoverability of long-lived assets; the estimation of the fair value of intangible assets; stock options; income tax uncertainties, including a valuation allowance for deferred tax assets; and contingencies. The Company bases these estimates on historical and anticipated results, trends, and various other assumptions that the Company believes are reasonable under the circumstances, including assumptions as to future events. These estimates form the basis for making judgments about the carrying values of assets and liabilities and recognized revenue and expenses that are not readily apparent from other sources. Actual results could differ from those estimates and assumptions.
Concentrations of Credit Risk and Other Risks and Uncertainties	Concentrations of Credit Risk and Other Risks and Uncertainties The majority of the Company's cash and cash equivalents are deposited with one major financial institution in the United States. Deposits in this institution may exceed the amount of insurance provided on such deposits. The Company has not experienced any losses on its deposits of cash and cash equivalents. Several of the components of the Company's sample collection kit and test reagents, and its nCounter FLEX DX systems and related test kits are obtained from single-source suppliers. If these single-source suppliers fail to satisfy the Company's requirements on a timely basis, it could suffer delays in being able to deliver its diagnostic solutions, a possible loss of revenue, or incur higher costs, any of which could adversely affect its operating results. The Company is also subject to credit risk from its accounts receivable related to its sales. The Company does not perform evaluations of customers' financial condition and does not require collateral.
Cash Equivalents	Cash Equivalents Cash equivalents consist of short-term, highly liquid investments with original maturities of three months or less from the date of purchase. Cash equivalents consist of amounts invested in a money market account primarily consisting of U.S. Treasury reserves, and overnight reverse repurchase agreements which are tri-party repurchase agreements and are collateralized by U.S. Treasury and agency securities of at least 102% of the principal amount. In a tri-party repurchase agreement, a third-party custodian bank functions as an independent intermediary to facilitate transfer of cash and holding the collateral on behalf of the underlying investor for the term of the agreement thereby minimizing risk and exposure to both parties. These overnight reverse repurchase agreements are included within cash equivalents due to their high liquidity and relatively low risk.
Restricted Cash	Restricted Cash The Company had deposits of $603,000 included in long-term assets as of December 31, 2019 and December 31, 2018 , restricted from withdrawal and held by a bank in the form of collateral for an irrevocable standby letter of credit held as security for the lease of the Company's South San Francisco facility.
Acquisitions	Acquisitions The Company first determines whether a set of assets acquired and liabilities assumed constitute a business and should be accounted for as a business combination. If the assets acquired are not a business, the Company accounts for the transaction as an asset acquisition. Business combinations are accounted for by using the acquisition method of accounting. Under the acquisition method, assets acquired, and liabilities assumed are recorded at their respective fair values as of the acquisition date in our consolidated financial statements. The excess of the fair value of consideration transferred over the fair value of the net assets acquired is recorded as goodwill. Contingent consideration obligations incurred in connection with a business combination are recorded at fair value on the acquisition date and remeasured at each subsequent reporting period until the related contingencies are resolved, with the resulting changes in fair value recorded in earnings.
Accounts Receivable and Allowance for Doubtful Accounts for Product Sales	Accounts Receivable and Allowance for Doubtful Accounts for Product Sales
Property and Equipment	Property and Equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation is computed using the straight-line method over the estimated useful lives of the assets, generally between three and five years . Leasehold improvements are amortized using the straight-line method over the shorter of the estimated useful life of the asset or the term of the lease. Maintenance and repairs are charged to expense as incurred, and improvements and betterments are capitalized. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in the statements of operations and comprehensive loss in the period realized.
Finite-lived Intangible Assets	Finite-lived Intangible Assets Finite-lived intangible assets consist of intangible assets acquired as part of business combinations. The Company amortizes finite-lived intangible assets using the straight-line method over their estimated useful lives of 5 to 15 years , based on management's estimate of the period over which their economic benefits will be realized, product life and patent life. The Company tests these finite-lived intangible assets for impairment when events or circumstances indicate a reduction in the fair value below their carrying amounts. There was no impairment for the years ended December 31, 2019 , 2018 or 2017 .
Goodwill	Goodwill Goodwill, derived from the Company's acquisition of Allegro Diagnostics Corp. in September 2014 and the exclusive global diagnostics license to the NanoString nCounter FLEX Analysis System and Prosigna and LymphMark assays in December 2019, is reviewed for impairment on an annual basis or more frequently if events or circumstances indicate that it may be impaired. The Company's goodwill evaluation is done annually on October 31 and is based on both qualitative and quantitative assessments regarding the fair value of goodwill relative to its carrying value. The Company has determined that it operates in a single segment and has a single reporting unit associated with the development and commercialization of diagnostic products. In the event the Company determines that it is more likely than not the carrying value of the reporting unit is higher than its fair value, quantitative testing is performed comparing recorded values to estimated fair values. If impairment is present, the impairment loss is measured as the excess of the recorded goodwill over its implied fair value. There was no impairment for the years ended December 31, 2019 , 2018 or 2017 .
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of certain financial instruments including cash and cash equivalents, accounts receivable, prepaid expenses and other current assets, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities.
Revenue Recognition and Cost of Revenue	Revenue Recognition Testing Revenue The Company commenced recognizing testing revenue in accordance with the provisions of ASC 606, Revenue from Contracts with Customers , or ASC 606, starting January 1, 2018. Prior to January 1, 2018, the Company recognized testing revenue in accordance with the provisions of ASC 954-605, Health Care Entities - Revenue Recognition , or ASC 954. Most of the Company’s revenue is generated from the provision of testing services. These services are completed upon the delivery of test results to the prescribing physician, at which time the Company bills for the services. The Company recognizes revenue related to billings based on estimates of the amount that will ultimately be realized. In determining the amount to accrue for a delivered test, the Company considers factors such as payment history, payer coverage, whether there is a reimbursement contract between the payer and the Company, payment as a percentage of agreed upon rate (if applicable), amount paid per test and any current developments or changes that could impact reimbursement. These estimates require significant judgment by management. The Company adopted ASC 606 on January 1, 2018 using the modified retrospective method, which requires a cumulative catch-up adjustment as if the Company had recognized revenue under ASC 606 from January 1, 2016. Prior to January 1, 2018, the Company recognized revenue in accordance with ASC 954 and recognized revenue for tests delivered on an accrual basis when amounts that will ultimately be realized could be reasonably estimated, and on the cash basis when there was insufficient information to estimate revenue accruals. There was sufficient payment history for the Company to substantially accrue all revenue upon delivery of test results starting July 1, 2016 and the Company continued to recognize revenue in 2017 upon cash receipt for unaccrued tests that were delivered prior to July 1, 2016. As noted above, on July 1, 2016 the Company began recognizing testing revenue from substantially all its tests on the accrual basis of accounting at an amount equal to management’s best estimate of the cash to ultimately be collected. For tests delivered prior to July 1, 2016, substantially all the related cash had been collected by December 31, 2017. Thus, at January 1, 2018, the cumulative impact of adopting ASC 606 was not material and no adjustment was recorded. Since the Company commenced recognizing revenue from substantially all of its tests on the accrual basis of accounting commencing on July 1, 2016, and continued to do so after the adoption of ASC 606, the adoption of ASC 606 did not have a material impact on the Company's statement of operations for the year ended December 31, 2019 . During 2019, the Company changed its testing revenue estimates due to actual and anticipated cash collections for tests delivered in 2018 or prior years and recognized additional revenue of $1.6 million , which resulted in a decrease in the Company's loss from operations of $1.6 million and a decrease in loss per share of $0.04 for the year ended December 31, 2019 . During 2018, the Company changed its testing revenue estimates due to actual and anticipated cash collections for tests delivered in 2017 or prior years and recognized additional revenue of $1.4 million , which resulted in a decrease in the Company's loss from operations of $1.4 million and a decrease in loss per share of $0.04 for the year ended December 31, 2018. Product Revenue The Company began recognizing product revenue in December 2019, when the Company executed an agreement with NanoString for the exclusive global license to the nCounter platform for diagnostic use. More details on this agreement are in Note 4 - Business Combination. Product revenue from instruments, consumables and in vitro diagnostic kits is recognized generally upon shipment or when the instrument is ready for use by the end customer, which is when title of the product has been transferred to the customer. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. Performance obligations are considered satisfied once the Company has transferred control of a product to the customer, meaning the customer has the ability to use and obtain the benefit of the product. The Company recognizes product revenue for satisfied performance obligations only when there are no uncertainties regarding payment terms or transfer of control. Shipping and handling costs incurred for product shipments are charged to the Company's customers and included in product revenue. Revenues are presented net of the taxes that are collected from customers and remitted to governmental authorities. There was no revenue from instrument sales for the years ended December 31, 2019, 2018 or 2017. Biopharmaceutical and Collaboration Revenue From time to time, the Company enters into arrangements for research and development and/or commercialization services. Such arrangements may require the Company to deliver various rights, services and/or samples, including intellectual property rights/licenses, R&D services, and/or commercialization services. The underlying terms of these arrangements generally provide for consideration to the Company in the form of nonrefundable upfront license fees, development and commercial performance milestone payments, royalty payments, and/or profit sharing. In arrangements involving more than one performance obligation, each required performance obligation is evaluated to determine whether it qualifies as a distinct performance obligation based on whether (i) the customer can benefit from the good or service either on its own or together with other resources that are readily available and (ii) the good or service is separately identifiable from other promises in the contract. The consideration under the arrangement is then allocated to each separate distinct performance obligation based on its respective relative stand-alone selling price. The estimated selling price of each deliverable reflects the Company's best estimate of what the selling price would be if the deliverable was regularly sold by the Company on a stand-alone basis or using an adjusted market assessment approach if selling price on a stand-alone basis is not available. The consideration allocated to each distinct performance obligation is recognized as revenue when control of the related goods is transferred or services are performed. Consideration associated with at-risk substantive performance milestones is recognized as revenue when it is probable that a significant reversal of the cumulative revenue recognized will not occur. Should there be royalties, the Company utilizes the sales and usage-based royalty exception in arrangements that resulted from the license of intellectual property, recognizing revenues generated from royalties or profit sharing as the underlying sales occur. Collaborative Arrangements The Company enters into collaborative arrangements with partners that fall under the scope of ASC Topic 808, Collaborative Arrangements (“ASC 808”). While these arrangements are in the scope of ASC 808, the Company may analogize to ASC 606 for some aspects of these arrangements. The Company analogizes to ASC 606 for certain activities within the collaborative arrangement for the delivery of a good or service (i.e., a unit of account) that is part of its ongoing major or central operations. The terms of the Company’s collaborative arrangements typically include one or more of the following: (i) up-front fees; (ii) milestone payments related to the achievement of development, regulatory, or commercial goals; and (iii) royalties on net sales of licensed products. Each of these payments may result in collaboration revenues or an offset against research and development expense. Net sales of data or other services to our customers are classified under biopharmaceutical revenue and collaboration revenue, such as milestones, are classified under collaboration revenue in our consolidated statements of operations and comprehensive loss. As part of the accounting for these arrangements, the Company must develop estimates and assumptions that require judgment to determine the underlying stand-alone selling price for each performance obligation which determines how the transaction price is allocated among the performance obligations. Generally, the estimation of the stand-alone selling price may include such estimates as independent evidence of market price, forecasted revenues or costs, development timelines, discount rates, and probabilities of technical and regulatory success. The Company evaluates each performance obligation to determine if they can be satisfied at a point in time or over time, and it measures the services delivered to the collaborative partner which are periodically reviewed based on the progress of the related program. The effect of any change made to an estimated input component and, therefore revenue or expense recognized, would be recorded as a change in estimate. In addition, variable consideration (e.g., milestone payments) must be evaluated to determine if it is constrained and, therefore, excluded from the transaction price. Up-front Fees: If a license to the Company’s intellectual property is determined to be distinct from the other performance obligations identified in the arrangement, the Company recognizes revenues from the transaction price allocated to the license when the license is transferred to the licensee and the licensee is able to use and benefit from the license. For licenses that are bundled with other promises, the Company utilizes judgment to assess the nature of the combined performance obligation to determine whether the combined performance obligation is satisfied over time or at a point in time. Milestone Payments: At the inception of each arrangement that includes milestone payments (variable consideration), the Company evaluates whether the milestones are considered probable of being reached and estimates the amount to be included in the transaction price using the most likely amount method. If it is probable that a significant revenue reversal would not occur, the associated milestone value is included in the transaction price. Milestone payments that are not within the Company’s or the collaborative partner’s control, such as non-operational developmental and regulatory approvals, are generally not considered probable of being achieved until those approvals are received. At the end of each reporting period, the Company re-evaluates the probability of achievement of milestones that are within its or the collaborative partner’s control, such as operational developmental milestones and any related constraint, and if necessary, adjusts its estimate of the overall transaction price. Any such adjustments are recorded on a cumulative catch-up basis, which would affect collaboration revenues and earnings in the period of adjustment. Revisions to the Company’s estimate of the transaction price may also result in negative collaboration revenues and earnings in the period of adjustment. Services Agreement with Loxo Oncology On April 9, 2018, the Company entered into an agreement with Loxo Oncology, Inc. ("Loxo") whereby the Company agreed to provide certain tissue samples and other services in exchange for agreed-upon fees. During the quarter ended June 30, 2018, the Company recognized $450,000 of revenue upon deliveries of tissue samples and the Company received $500,000 for other services, which was recognized ratably during the quarters ended September 30 and December 31, 2018 as the services were performed. Thereafter, the Company expects to receive approximately $250,000 per quarter as services are performed and may also recognize revenue related to the deliveries of additional tissue samples as long as the agreement is not terminated. The agreement has a one -year term with an automatic renewal of one year and Loxo may terminate the agreement at any time with at least 90 days' notice. As of December 31, 2019, the agreement had not been terminated. The Company evaluated the accounting for this agreement under ASC 606 and concluded that the performance obligations thereunder are the deliveries of tissue samples and performance of services, both of which are distinct. For the year ended December 31, 2019 , the Company recognized revenue of $90,000 for deliveries of tissue samples and $1,000,000 for the performance of services and is classified under biopharmaceutical revenue in the Consolidated Statement of Operations and Comprehensive Loss. There was no deferred revenue related to this agreement at December 31, 2019 . Diagnostic Development Agreement with Johnson & Johnson On December 28, 2018, the Company entered into a diagnostics development agreement with Johnson and Johnson Services, Inc. ("JJSI") (i) to cooperate on a program to enable the Company to use JJSI samples and clinical data to develop a next generation bronchial genomic classifier diagnostic for lung cancer diagnosis (“Percepta v.2") and a nasal genomic classifier diagnostic for lung cancer (“NasaRISK”) and (ii) for JJSI to use Veracyte data generated in two Veracyte development programs for therapeutic purposes and for purposes of developing a companion diagnostic product used in conjunction with a JJSI therapeutic. The Company granted a license to JJSI with the right to use data and under the Company's intellectual property rights for JJSI's therapeutic purposes, including the development and commercialization of a companion diagnostic for its products, from the Percepta v.2 and NasaRISK programs. The license granted to JJSI is not distinct from other performance obligations as JJSI receives benefit only when other performance obligations are met. Under the terms of the agreement, the Company will provide data from its RNA whole-transcriptome sequencing platform to JJSI in exchange for $7.0 million in payments from JJSI. The Company is also entitled to additional payments from JJSI of up to $13.0 million , conditioned upon the achievement of certain milestones relating to the development and reimbursement of Percepta v.2 and NasaRISK. For a period of ten years commencing with the first commercial sale of Percepta v.2 and NasaRISK, respectively, the Company will make payments to JJSI of one percent of net cash collections for Percepta v.2 and in the low-single digits of net cash collections for NasaRISK, depending on the number and timing of JJSI samples and associated clinical data the Company receives from JJSI. The JJSI agreement is considered to be within the scope of ASC 808, as the parties are active participants and exposed to the risks and rewards of the collaborative activity. The Company evaluated the terms of the JJSI agreement and has analogized to ASC 606 for the delivery of data from its RNA whole-transcriptome sequencing platform to JJSI under the collaborative arrangement, which the Company believes is a distinct service for which JJSI meets the definition of a customer. Using the concepts of ASC 606, the Company has identified the delivery of data as its only performance obligation. The Company further determined that the transaction price under the arrangement was the $7.0 million in payments which was allocated to the obligation to deliver data. The $13.0 million in future potential payments is considered variable consideration because the Company determined that the potential payments are contingent upon regulatory and commercialization milestones that are uncertain to occur and, as such, were not included in the transaction price, and will be recognized accordingly as each potential payment becomes probable. The Company recognized revenue of $7.0 million and $4.0 million during 2019 for the provision of data and fulfillment of obligations relating to Percepta v.2 and NasaRISK development milestones, respectively. This revenue is classified under biopharmaceutical revenue and collaboration revenue, respectively, in the consolidated statement of operations and comprehensive loss. Accounts receivable from JJSI was $2.0 million at December 31, 2019 . The cost of biopharmaceutical revenue recognized under the agreement with JJSI is not significant and recorded in research and development in the statement of operations and comprehensive loss. There was no deferred revenue related to this agreement at December 31, 2019 . Collaboration Agreement with AstraZeneca Group On December 23, 2019, the Company entered into an agreement with Acerta Pharma B.V. ("Acerta"), a member of AstraZeneca Group whereby the Company agreed to provide genomic information that will support Acerta’s development of oncology therapeutics. Acerta will reimburse the Company for certain development costs and pay milestones to the Company for the achievement of development milestones. As of December 31, 2019, there was no performance of obligations under the agreement or consideration paid. The agreement will be accounted for in accordance with the policy on collaborative arrangements, as mentioned in this footnote. Cost of Testing Revenue The components of our cost of testing services are laboratory expenses, sample collection expenses, compensation expense, license fees and royalties, depreciation and amortization, other expenses such as equipment and laboratory supplies, and allocations of facility and information technology expenses. Costs associated with performing tests are expensed as the test is processed regardless of whether and when revenue is recognized with respect to that test.
Research and Development	Research and Development Research and development expenses include expenses incurred to develop our technology, collect clinical samples and conduct clinical studies to develop and support our products. These expenses consist of compensation expenses, direct research and development expenses such as prototype materials, laboratory supplies and costs associated with setting up and conducting clinical studies at domestic and international sites, professional fees, depreciation and amortization, other miscellaneous expenses and allocation of facility and information technology expenses. We expense all research and development costs in the periods in which they are incurred.
Income Taxes	Income Taxes The Company accounts for income taxes under the liability method. Under this method, deferred tax assets and liabilities are determined based on the difference between the financial statement and tax bases of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to affect taxable income. Valuation allowances are established when necessary to reduce deferred tax assets to the amounts expected to be realized. The Company assesses all material positions taken in any income tax return, including all significant uncertain positions, in all tax years that are still subject to assessment or challenge by relevant taxing authorities. The Company's assessment of an uncertain tax position begins with the initial determination of the position's sustainability and is measured at the largest amount of benefit that is more-likely-than-not of being realized upon ultimate settlement. As of each balance sheet date, unresolved uncertain tax positions must be reassessed, and the Company will determine whether (i) the factors underlying the sustainability assertion have changed and (ii) the amount of the recognized tax benefit is still appropriate. The recognition and measurement of tax benefits requires significant judgment. Judgments concerning the recognition and measurement of a tax benefit may change as new information becomes available.
Stock-based Compensation	Stock-based Compensation Stock-based compensation expense for stock options issued to employees is measured based on the grant-date fair value of the award. The fair value of each employee stock option is estimated on the date of grant using the Black-Scholes option-pricing model. Stock-based compensation expense for stock units is measured based on the fair value of the award, which is determined based upon the closing price of the Company’s common stock on the date of the grant. The Company grants performance-based stock units to certain employees which vest upon the achievement of certain performance conditions, subject to the employees’ continued service with the Company. The probability of vesting is assessed at each reporting period and compensation cost is adjusted based on this probability assessment. The Company recognizes compensation costs on a straight-line basis for all employee stock-based compensation awards that are expected to vest over the requisite service period of the awards, which is generally the awards' vesting period. Forfeitures are required to be estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures differ from those estimates. Following the adoption of ASU No. 2018-07, Compensation - Stock Compensation (Topic 718): Improvements to Nonemployee Share Based Payment Accounting
Net Loss per Common Share	Net Loss per Common Share Basic net loss per common share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period, without consideration of common stock equivalents. Diluted net loss per common share is computed by dividing net loss attributable to common stockholders by the weighted-average number of common share equivalents outstanding for the period determined using the treasury stock method. Potentially dilutive securities consisting of options to purchase common stock, restricted stock units and shares subject to purchase under our employee stock purchase plan are considered to be common stock equivalents and were excluded from the calculation of diluted net loss per common share because their effect would be anti-dilutive for all periods presented.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In February 2016, the FASB issued ASU No. 2016-2, Leases (Topic 842) . This ASU is aimed at making leasing activities more transparent and comparable, and requires substantially all leases be recognized by lessees on their balance sheet as a right-of-use asset and corresponding lease liability, including leases currently accounted for as operating leases. The ASU was effective for interim and annual periods beginning after December 15, 2018. Additionally, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted Improvements , which offers an additional transition method whereby entities may apply the new leases standard at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings rather than application of the new leases standard at the beginning of the earliest period presented in the financial statements. The Company elected this transition method and adopted ASC 842 on January 1, 2019 and as a result, recorded operating lease right-of-use ("ROU") assets of $9.8 million , including offsetting deferred rent of $4.3 million , along with the associated operating lease liabilities of $14.1 million . On January 1, 2019, the Company had finance lease ROU assets of $0.8 million and associated finance lease liabilities of $0.3 million for leases classified as finance leases prior to the adoption of ASC 842. The adoption of ASC 842 had an immaterial impact on the Company's consolidated statement of operations and comprehensive loss, consolidated statement of stockholders' equity and consolidated statement of cash flows for the year ended December 31, 2019. In addition, the Company elected the package of practical expedients permitted under the transition guidance within the new standard which allowed it to carry forward the historical lease classification. Additional information and disclosures required by this new standard are contained in Note 7, Commitments and Contingencies. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses: Measurement of Credit Losses on Financial Instruments . This ASU requires measurement and recognition of expected credit losses for financial assets. This guidance will become effective for the Company beginning January 1, 2020 with early adoption permitted. The Company does not expect to have a material impact on its financial statements and related disclosures from the adoption of this guidance. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808).

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2019
Revenues [Abstract]
Schedule of Revenue recognized when cash is received and on an accrual basis	Testing revenue recognized for the years ended December 31, 2019 , 2018 and 2017 was as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Testing revenue recognized on the accrual basis $ 107,355 100 % $ 91,058 100 % $ 69,274 96 % Testing revenue recognized on the cash basis — — % — — % 2,679 4 % Total $ 107,355 100 % $ 91,058 100 % $ 71,953 100 %
Revenue concentration risk \| Revenue
Concentration Risk
Schedule of the Company's third-party payers as a percentage of total	The Company's third-party payers and other customers in excess of 10% of revenue and their related revenue as a percentage of total revenue were as follows: Year Ended December 31, 2019 2018 2017 Medicare 26 % 29 % 26 % UnitedHealthcare 11 % 12 % 14 % 37 % 41 % 40 %
Gross receivables concentration risk \| Accounts receivable
Concentration Risk
Schedule of the Company's third-party payers as a percentage of total	The Company's significant third-party payers and other customers in excess of 10% of accounts receivable and their related accounts receivable balance as a percentage of total accounts receivable were as follows: As of December 31, 2019 2018 Medicare 15 % 20 % Johnson and Johnson Services, Inc. 10 % — % UnitedHealthcare 9 % 11 %

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	12 Months Ended
Net Loss Per Share (Tables)	Dec. 31, 2019
Earnings Per Share [Abstract]
Schedule of outstanding shares of common stock equivalents that have been excluded from diluted net loss per common share	The following outstanding common stock equivalents have been excluded from diluted net loss per common share for the years ended December 31, 2019 , 2018 and 2017 because their inclusion would be anti-dilutive: Year Ended December 31, 2019 2018 2017 Shares of common stock subject to outstanding options 5,394,944 5,998,163 6,163,734 Employee stock purchase plan 26,124 34,869 34,559 Restricted stock units 712,122 384,691 63,425 Total common stock equivalents 6,133,190 6,417,723 6,261,718

Business Combination (Tables)

Business Combination (Tables)	12 Months Ended
Business Combination (Tables)	Dec. 31, 2019
Business Combinations [Abstract]
Schedule of fair value of assets acquired and liabilities assumed	The following table summarizes the fair values of assets acquired and liabilities assumed at the date of acquisition (in thousands): Prosigna product technology $ 4,120 Prosigna customer relationships 2,430 nCounter FLEX Dx license 46,880 LymphMark product technology 990 Total identifiable intangible assets acquired 54,420 Goodwill 1,668 Net assets acquired $ 56,088
Schedule of identifiable acquisition-related intangibles	Identifiable acquisition-related intangibles included in the above table are finite-lived and are being amortized on a straight-line basis over their estimated lives, which approximates the pattern in which the economic benefits of the intangible assets are expected to be realized, as follows: Estimated Useful life (In Years) Prosigna product technology 15 Prosigna customer relationships 5 nCounter FLEX Dx license 15 LymphMark product technology 7
Pro forma financial information	The unaudited pro forma revenue information is for informational purposes only and is not necessarily indicative of the revenue that would have been achieved if the acquisition had taken place as of January 1, 2018 (in thousands): Year Ended December 31, 2019 2018 Product revenue $ 11,040 $ 11,482

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
Balance Sheet Components (Tables)	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule of property and equipment	Property and equipment consisted of the following (in thousands of dollars): December 31, 2019 2018 Leasehold improvements $ 5,926 $ 5,825 Laboratory equipment 9,655 8,895 Computer equipment 1,709 1,615 Software, including software developed for internal use 3,226 2,450 Furniture and fixtures 1,482 1,435 Construction-in-process 1,015 726 Total property and equipment, at cost 23,013 20,946 Accumulated depreciation and amortization (14,080 ) (12,006 ) Total property and equipment, net $ 8,933 $ 8,940
Schedule of finite-lived intangible assets	Finite-live intangible assets consisted of the following (in thousands of dollars): December 31, 2019 December 31, 2018 Weighted Average Amortization Period (Years) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Gross Carrying Amount Accumulated Amortization Net Carrying Amount Percepta product technology $ 16,000 $ (5,067 ) $ 10,933 $ 16,000 $ (4,000 ) $ 12,000 15 Prosigna product technology 4,120 (17 ) 4,103 — — — 15 Prosigna customer relationships 2,430 (42 ) 2,388 — — — 5 nCounter FLEX Dx license 46,880 (263 ) 46,617 — — — 15 LymphMark product technology 990 (12 ) 978 — — — 7 Total $ 70,420 $ (5,401 ) $ 65,019 $ 16,000 $ (4,000 ) $ 12,000 14.5
Schedule of future amortization	The estimated future aggregate amortization expense as of December 31, 2019 is as follows (in thousands of dollars): Year Ending December 31, Amounts 2020 $ 5,095 2021 5,094 2022 5,094 2023 5,094 2024 5,054 Thereafter 39,588 Total $ 65,019
Schedule of accrued liabilities	Accrued liabilities consisted of the following (in thousands of dollars): December 31, 2019 2018 Accrued compensation expense $ 10,100 $ 6,412 Accrued other 3,634 2,774 Total accrued liabilities $ 13,734 $ 9,186

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum lease payments under non-cancelable operating leases	Future minimum lease payments under non-cancelable operating leases as of December 31, 2019 are as follows (in thousands of dollars): Year Ending December 31, Amounts 2020 $ 2,332 2021 2,401 2022 2,472 2023 2,543 2024 2,614 Thereafter 4,226 Total future minimum lease payments 16,588 Less: amount representing interest 3,675 Present value of future lease payments 12,913 Less: short-term lease liabilities 1,407 Long-term lease liabilities $ 11,506

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of net debt obligation	As of December 31, 2019 and 2018 , the net debt obligation for borrowings made under the Loan and Security Agreement was as follows (in thousands of dollars): December 31, 2019 2018 Debt principal $ 100 $ 25,000 End-of-term debt obligation 594 365 Unamortized debt issuance costs — (83 ) Net debt obligation $ 694 $ 25,282
Schedule of interest expense on debt	Interest expense was recognized as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Nominal debt interest $ 332 $ 1,568 $ 2,838 Amortization and write-off of debt discount and issuance costs 107 57 472 End-of-term debt obligation interest 229 312 53 Debt prepayment penalty — — 1,536 Interest on capital lease 9 26 42 Total $ 677 $ 1,963 $ 4,941

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
Stockholders' Equity (Tables)	Dec. 31, 2019
Equity [Abstract]
Schedule of reserved shares of common stock for issuance	As of December 31, 2019 and 2018 , the Company had reserved shares of common stock for issuance as follows: December 31, 2019 2018 Stock options and restricted stock units issued and outstanding 5,562,484 6,235,258 Stock options and restricted stock units available for grant under stock option plans 1,954,804 1,571,658 Common stock available for the Employee Stock Purchase Plan 173,168 309,419 Total 7,690,456 8,116,335

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	12 Months Ended
Stock Incentive Plans (Tables)	Dec. 31, 2019
Stock incentive plans
Summary of activity under the Company's stock option plans	The following table summarizes activity under the Company's stock incentive plans (aggregate intrinsic value in thousands): Shares Available for Grant Stock Options Weighted Weighted Average Aggregate Balance—December 31, 2018 1,571,658 6,235,258 $ 7.95 6.95 $ 27,340 Additional shares authorized 1,634,528 — Granted - stock options (969,500 ) 969,500 21.16 Granted - restricted stock units (505,965 ) 505,965 Canceled 180,017 (180,017 ) 9.40 Exercised — (1,846,222 ) 7.77 Restricted stock units vested — (122,000 ) Tax portion of restricted stock units vested 44,066 — Balance—December 31, 2019 1,954,804 5,562,484 $ 10.66 6.97 $ 79,760 Options vested and exercisable—December 31, 2019 2,651,858 $ 8.13 5.90 $ 52,469 Options vested and expected to vest—December 31, 2019 4,442,275 $ 10.48 6.91 $ 77,453
Stock-based Compensation
Stock incentive plans
Summary of share-based compensation expense	The following table summarizes stock-based compensation expense related to stock options, restricted stock units and the ESPP for the years ended December 31, 2019, 2018 and 2017, and are included in the consolidated statements of operations and comprehensive loss as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Cost of testing revenue $ 277 $ 130 $ 133 Research and development 1,856 1,018 1,495 Selling and marketing 2,938 1,866 1,899 General and administrative 4,736 2,944 3,090 Total stock-based compensation expense $ 9,807 $ 5,958 $ 6,617
Stock-based Compensation, employees
Stock incentive plans
Schedule of assumptions used to calculate estimated grant date fair value of stock options using the Black-Scholes option-pricing valuation model	The estimated grant-date fair value of employee stock options was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility 52.90 - 53.40% 50.40 - 52.70% 50.40 - 52.40% Weighted-average expected term (years) 5.50 - 6.08 5.50 - 6.08 5.50 - 6.08 Risk-free interest rate 1.90 - 2.60% 2.40 - 3.10% 1.80 - 2.33% Expected dividend yield — — —
Stock-based Compensation, non-employees
Stock incentive plans
Schedule of assumptions used to calculate estimated grant date fair value of stock options using the Black-Scholes option-pricing valuation model	The estimated fair value of non-employee stock options was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility —% 43.60 - 50.50% 50.40 - 51.10% Weighted-average expected term (years) — 0.25 - 6.75 6.80 - 7.75 Risk-free interest rate —% 1.84 - 2.87% 2.16 - 2.37% Expected dividend yield — — —
Employee stock purchase plan
Stock incentive plans
Schedule of assumptions used to calculate estimated grant date fair value of stock options using the Black-Scholes option-pricing valuation model	There were no non-employee stock options outstanding as of December 31, 2019. The estimated grant date fair value of the ESPP shares was calculated using the Black-Scholes option-pricing model, based on the following assumptions: Year Ended December 31, 2019 2018 2017 Weighted-average volatility 53.38 - 71.77% 42.88 - 47.74% 37.00 - 43.86% Weighted-average expected term (years) 0.50 - 1.00 0.50 - 1.00 0.50 - 1.00 Risk-free interest rate 1.88 - 2.56% 1.64 - 2.45% 0.65 - 1.22% Expected dividend yield — — —

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of reconciliation of tax expense computed at the statutory federal rate and the Company's tax expense	The following table presents a reconciliation of the income tax expense computed at the statutory federal rate and the Company's income tax expense for the periods presented (in thousands of dollars): Year Ended December, 31, 2019 2018 2017 U.S. federal taxes at statutory rate $ (2,632 ) $ (4,825 ) $ (10,541 ) State tax (net of federal benefit) (828 ) — 15 Non deductible officers' compensation 439 409 — Stock based compensation - PSU/RSU/NQSQ 628 — — Permanent differences 221 285 198 Incentive stock options (4,994 ) (256 ) 994 Tax credits (996 ) (777 ) (588 ) Change in valuation allowance 8,162 5,164 (14,552 ) Rate differential impact - Tax Cuts and Jobs Act — — 24,474 Total $ — $ — $ —
Schedule of significant components of the Company's deferred tax assets and liabilities	Significant components of the Company's deferred tax assets and liabilities are as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 56,506 $ 50,410 $ 47,177 Research and development credits 5,579 4,584 4,034 Stock-based compensation 2,246 1,032 2,068 NanoString intangibles and goodwill 380 — — Operating lease liability 3,068 — — Accruals and other 2,610 2,918 2,375 Gross deferred tax assets 70,389 58,944 55,654 Valuation allowance (65,228 ) (55,366 ) (51,657 ) Net deferred tax assets 5,161 3,578 3,997 Deferred tax liabilities: Property and equipment (471 ) (695 ) (983 ) In-process research and development (2,597 ) (2,883 ) (3,014 ) ROU assets (2,093 ) — — Gross deferred tax liabilities (5,161 ) (3,578 ) (3,997 ) Net deferred tax liabilities (5,161 ) (3,578 ) (3,997 ) Net deferred taxes $ — $ — $ —
Schedule of reconciliation of the beginning and ending amount of unrecognized tax benefits	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands of dollars): Year Ended December 31, 2019 2018 2017 Unrecognized tax benefits, beginning of period $ 2,799 $ 2,523 $ 2,222 Gross increases—tax position in prior period — — — Gross decreases—tax position in prior period — (97 ) — Gross increases—current period tax position 479 373 301 Lapse of statute of limitations — — — Unrecognized tax benefits, end of period $ 3,278 $ 2,799 $ 2,523

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
Selected Quarterly Financial Data (Unaudited) (Tables)	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of selected quarterly financial data (unaudited)	The results of operations for any quarter are not necessarily indicative of the results to be expected for any future period (in thousands of dollars, except for share and per share data): Quarter Ended March 31 June 30 September 30 December 31 2019: Revenue $ 29,529 $ 30,136 $ 30,973 $ 29,730 Net loss (1,917 ) (2,494 ) (730 ) (7,458 ) Net loss per common share, basic and diluted (0.05 ) (0.05 ) (0.02 ) (0.15 ) Shares used to compute net loss per common share, basic and diluted 41,168,593 45,586,081 48,588,296 49,095,703 2018: Revenue $ 20,041 $ 22,751 $ 23,466 $ 25,750 Net loss (9,177 ) (6,248 ) (4,469 ) (3,105 ) Net loss per common share, basic and diluted (0.27 ) (0.18 ) (0.12 ) (0.08 ) Shares used to compute net loss per common share, basic and diluted 34,271,254 34,314,234 38,620,036 40,731,334

Organization and Description _2

Organization and Description of Business (Details)	12 Months Ended
Organization and Description of Business (Details)	Dec. 31, 2019segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments (in segments)	1

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Liquidity (Details) - USD ($) $ / shares in Units, $ in Thousands	May 07, 2019	Jul. 31, 2018	Nov. 30, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liquidity
Accumulated deficit				$ 246,685	$ 234,086
Cash and cash equivalents				$ 159,317	$ 77,995	$ 33,891
Stock issued during the period (in shares)	6,325,000
Sale of stock (in usd per share)	$ 23.25
Proceeds from issuance of common stock	$ 137,800
Number of shares issued in transaction (in shares)		5,750,000
Payments of stock issuance costs	$ 9,200
Revolving credit facility \| Line of credit \| Silicon Valley Bank
Liquidity
Proceeds from long-term lines of credit			$ 25,000
Over-Allotment Option
Liquidity
Stock issued during the period (in shares)	825,000
Number of shares issued in transaction (in shares)		750,000
Proceeds from issuance of common stock		$ 55,000
Payments of stock issuance costs		$ 3,900
Common Stock \| Over-Allotment Option
Liquidity
Shares issued, price per share (in usd per share)		$ 10.25

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Credit Risk, Restricted Cash, and Allowance for Doubtful Accounts (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)financial_institution	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Concentrations of Credit Risk and Other Risks and Uncertainties
Number of major financial institutions with which the company's cash and cash equivalents are deposited (in financial institutions) \| financial_institution	1
Restricted Cash
Long term deposit consisting of letter of credit serving as security for lease \| $	$ 603	$ 603	$ 603
Revenue \| Revenue concentration risk
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	37.00%	41.00%	40.00%
Revenue \| Revenue concentration risk \| Medicare
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	26.00%	29.00%	26.00%
Revenue \| Revenue concentration risk \| United Healthcare
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	11.00%	12.00%	14.00%
Accounts receivable \| Gross receivables concentration risk \| Medicare
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	15.00%	20.00%
Accounts receivable \| Gross receivables concentration risk \| Johnson and Johnson Services, Inc.
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	10.00%	0.00%
Accounts receivable \| Gross receivables concentration risk \| United Healthcare
Concentrations of Credit Risk and Other Risks and Uncertainties
Concentration risk	9.00%	11.00%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Intangible Assets, Bonus Accruals, and Revenue Recognition (Details) - USD ($)	Apr. 09, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finite-lived Intangible Assets
Weighted Average Amortization Period (Years)										14 years 6 months
Finite-lived intangible assets, impairment										$ 0	$ 0	$ 0
Goodwill
Goodwill impairment										0	0	0
Revenue Recognition
Total		$ 29,730,000	$ 30,973,000	$ 30,136,000	$ 29,529,000	$ 25,750,000	$ 23,466,000	$ 22,751,000	$ 20,041,000	120,368,000	92,008,000	71,953,000
Income (loss) from operations										$ (15,127,000)	$ (22,233,000)	$ (26,538,000)
Net income (loss) per common share, basic and diluted (in dollars per share)		$ (0.15)	$ (0.02)	$ (0.05)	$ (0.05)	$ (0.08)	$ (0.12)	$ (0.18)	$ (0.27)	$ (0.27)	$ (0.62)	$ (0.91)
Biopharmaceutical Company
Revenue Recognition
Deferred revenue		$ 0								$ 0
ASU 2014-09
Revenue Recognition
Deferred revenue		1,600,000				$ 1,400,000				1,600,000	$ 1,400,000
Income (loss) from operations										$ 1,600,000	$ 1,400,000
Net income (loss) per common share, basic and diluted (in dollars per share)										$ 0.04	$ 0.04
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Useful lives										3 years
Finite-lived Intangible Assets
Weighted Average Amortization Period (Years)										5 years
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Useful lives										5 years
Finite-lived Intangible Assets
Weighted Average Amortization Period (Years)										15 years
Testing revenue
Revenue Recognition
Revenue recognized on an accrual basis										$ 107,355,000	$ 91,058,000	$ 69,274,000
Revenue recognized on a cash basis										0	0	2,679,000
Total										107,355,000	91,058,000	71,953,000
Product revenue
Revenue Recognition
Total										923,000	$ 0	$ 0
Product revenue \| Biopharmaceutical Company
Revenue Recognition
Contract with customer, revenue recognized								$ 450,000		90,000
Contract agreement term	1 year
Automatic renewal period of contract agreement	1 year
Service
Revenue Recognition
Revenue, amount of remaining performance obligation								$ 500,000
Service \| Biopharmaceutical Company
Revenue Recognition
Contract with customer, revenue recognized										1,000,000
Revenue, quarterly amount of remaining performance obligation		$ 250,000								$ 250,000
Product Concentration Risk \| Revenue from Contract with Customer, Product and Service Benchmark \| Testing revenue
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk										100.00%	100.00%	100.00%
Revenue Recognition
Revenue recognized on accrual basis, percentage										100.00%	100.00%	96.00%
Revenue recognized received in cash, percentage										0.00%	0.00%	4.00%
Johnson and Johnson Services, Inc.
Revenue Recognition
Contract agreement term										10 years
Johnson and Johnson Services, Inc. \| Gross receivables concentration risk \| Accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Concentration risk										10.00%	0.00%

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Diagnostic Development Agreement with Johnson & Johnson (Details)

Dec. 28, 2018USD ($)program

Dec. 31, 2019USD ($)

Sep. 30, 2019USD ($)

Jun. 30, 2019USD ($)

Mar. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Sep. 30, 2018USD ($)

Jun. 30, 2018USD ($)

Mar. 31, 2018USD ($)

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Revenue, Major Customer [Line Items]

Development programs | program

Accounts receivable, current

$ 13,000,000

Revenue

$ 29,730,000

$ 30,973,000

$ 30,136,000

$ 29,529,000

$ 25,750,000

$ 23,466,000

$ 22,751,000

$ 20,041,000

$ 120,368,000

$ 92,008,000

$ 71,953,000

Johnson and Johnson Services, Inc.

Revenue, Major Customer [Line Items]

Contract agreement receivable for services

$ 7,000,000

Contract agreement term

10 years

Percent of collections

1.00%

Percepta v.2 and Nassa Risk

Revenue, Major Customer [Line Items]

Accounts receivable

2,000,000

$ 2,000,000

Deferred revenue

$ 0

Provision of Data | Johnson and Johnson Services, Inc.

Revenue, Major Customer [Line Items]

Revenue

7,000,000

Fulfillment of Obligations | Johnson and Johnson Services, Inc.

Revenue, Major Customer [Line Items]

Revenue

$ 4,000,000

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets - operating lease	$ 8,808		$ 0
Operating lease, liability	$ 12,913
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets - operating lease		$ 9,800
Deferred revenue		4,300
Operating lease, liability		14,100
Right-of-use assets - finance lease		800
Finance lease, liability		$ 300

Net Loss Per Share (Details)

Net Loss Per Share (Details) - shares	12 Months Ended
Net Loss Per Share (Details) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Outstanding shares of common stock equivalents that have been excluded from diluted net loss per common share
Shares of common stock subject to outstanding options (in shares)	6,133,190	6,417,723	6,261,718
Shares of common stock subject to outstanding options
Outstanding shares of common stock equivalents that have been excluded from diluted net loss per common share
Shares of common stock subject to outstanding options (in shares)	5,394,944	5,998,163	6,163,734
Employee stock purchase plan
Outstanding shares of common stock equivalents that have been excluded from diluted net loss per common share
Shares of common stock subject to outstanding options (in shares)	26,124	34,869	34,559
Restricted stock units
Outstanding shares of common stock equivalents that have been excluded from diluted net loss per common share
Shares of common stock subject to outstanding options (in shares)	712,122	384,691	63,425

Business Combination (Details)

Business Combination (Details) - USD ($) $ in Thousands	Dec. 03, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Combination
Shares issued for purchase consideration for a business combination		$ 10,000	$ 0	$ 0
Acquisition related contingent consideration		6,088	0
Goodwill		$ 2,725	$ 1,057
NanoString
Business Combination
Cash paid in acquisition	$ 40,000
Additional cash to be paid	10,000
Acquisition related contingent consideration	6,100
Goodwill	1,668
Common Stock \| NanoString
Business Combination
Shares issued for purchase consideration for a business combination	$ 10,000

Business Combination - Schedule

Business Combination - Schedule of Fair Value of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 03, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Goodwill	$ 2,725		$ 1,057
NanoString
Business Acquisition [Line Items]
Total identifiable intangible assets acquired		$ 54,420
Goodwill		1,668
Net assets acquired		56,088
Prosigna product technology \| NanoString
Business Acquisition [Line Items]
Total identifiable intangible assets acquired		4,120
Prosigna customer relationships \| NanoString
Business Acquisition [Line Items]
Total identifiable intangible assets acquired		2,430
nCounter FLEX Dx license \| NanoString
Business Acquisition [Line Items]
Total identifiable intangible assets acquired		46,880
LymphMark product technology \| NanoString
Business Acquisition [Line Items]
Total identifiable intangible assets acquired		$ 990

Business Combination - Schedu_2

Business Combination - Schedule of Identifiable Acquisition-Related Intangibles (Details) - NanoString	Dec. 03, 2019
Prosigna product technology
Business Acquisition [Line Items]
Estimated Useful life (In Years)	15 years
Prosigna customer relationships
Business Acquisition [Line Items]
Estimated Useful life (In Years)	5 years
nCounter FLEX Dx license
Business Acquisition [Line Items]
Estimated Useful life (In Years)	15 years
LymphMark product technology
Business Acquisition [Line Items]
Estimated Useful life (In Years)	7 years

Business Combination - Pro form

Business Combination - Pro forma financial information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Product revenue \| NanoString
Business Acquisition [Line Items]
Total revenue	$ 11,040	$ 11,482

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property and Equipment, Net
Total property and equipment, at cost	$ 23,013	$ 20,946
Accumulated depreciation and amortization	(14,080)	(12,006)
Total property and equipment, net	8,933	8,940
Depreciation and amortization expense	2,700	2,900	$ 2,800
Capital leased assets	1,200
Accumulated depreciation	600	367
Capital leases, depreciation expense	233	232	$ 135
Leasehold improvements
Property and Equipment, Net
Total property and equipment, at cost	5,926	5,825
Laboratory equipment
Property and Equipment, Net
Total property and equipment, at cost	9,655	8,895
Computer equipment
Property and Equipment, Net
Total property and equipment, at cost	1,709	1,615
Software, including software developed for internal use
Property and Equipment, Net
Total property and equipment, at cost	3,226	2,450
Furniture and fixtures
Property and Equipment, Net
Total property and equipment, at cost	1,482	1,435
Construction-in-process
Property and Equipment, Net
Total property and equipment, at cost	$ 1,015	$ 726

Balance Sheet Components - Fini

Balance Sheet Components - Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 70,420	$ 16,000
Accumulated Amortization	(5,401)	(4,000)
Net Carrying Amount	$ 65,019	12,000
Weighted Average Amortization Period (Years)	14 years 6 months
Percepta technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 16,000	16,000
Accumulated Amortization	(5,067)	(4,000)
Net Carrying Amount	$ 10,933	12,000
Weighted Average Amortization Period (Years)	15 years
Prosigna product technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 4,120	0
Accumulated Amortization	(17)	0
Net Carrying Amount	$ 4,103	0
Weighted Average Amortization Period (Years)	15 years
Prosigna customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,430	0
Accumulated Amortization	(42)	0
Net Carrying Amount	$ 2,388	0
Weighted Average Amortization Period (Years)	5 years
nCounter FLEX Dx license
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 46,880	0
Accumulated Amortization	(263)	0
Net Carrying Amount	$ 46,617	0
Weighted Average Amortization Period (Years)	15 years
LymphMark product technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 990	0
Accumulated Amortization	(12)	0
Net Carrying Amount	$ 978	$ 0
Weighted Average Amortization Period (Years)	7 years

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Balance Sheet Related Disclosures [Abstract]
Amortization of intangible assets	$ 1.4	$ 1.1	$ 1.1

Balance Sheet Components - Futu

Balance Sheet Components - Future Amortization (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance Sheet Related Disclosures [Abstract]
2020	$ 5,095
2021	5,094
2022	5,094
2023	5,094
2024	5,054
Thereafter	39,588
Net Carrying Amount	$ 65,019	$ 12,000

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accrued Liabilities
Accrued compensation expense	$ 10,100	$ 6,412
Accrued other	3,634	2,774
Total accrued liabilities	$ 13,734	$ 9,186

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 03, 2019	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition related contingent consideration		$ 6,088	$ 0
Headquarters and laboratory facilities, South San Francisco, Lease signed in April 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Security deposit		603	603
Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		57,600	76,600
Fair Value, Inputs, Level 2 \| Overnight Repurchase Agreements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		$ 100,000	$ 0
NanoString
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Acquisition related contingent consideration	$ 6,100
Additional cash to be paid	$ 10,000

Commitments and Contingencies -

Commitments and Contingencies - Operating Lease (Details) ft² in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)ft²	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Operating Leases
Discount rate	7.53%
Facilities rent expense	$ 1,900	$ 1,900	$ 1,900
Purchase obligation	7,600
Future minimum lease payments under non-cancelable operating leases
2020	2,332
2021	2,401
2022	2,472
2023	2,543
2024	2,614
Thereafter	4,226
Total future minimum lease payments	16,588
Less: amount representing interest	3,675
Present value of future lease payments	12,913
Less: short-term lease liabilities	1,407	0
Long-term lease liabilities	$ 11,506	0
Headquarters and laboratory facilities, South San Francisco, Lease signed in April 2015
Operating Leases
Amount of space leased (in square feet) \| ft²	59
Security deposit	$ 603	603
Laboratory facilities, Austin, Texas
Operating Leases
Security deposit	$ 139	$ 139

Debt - Loan and Security Agreem

Debt - Loan and Security Agreement (Details) - USD ($)	Nov. 03, 2017	May 31, 2019	Jan. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Line of Credit Facility [Line Items]
Repayments of long-term debt				$ 24,900,000	$ 0	$ 25,385,000
Line of credit
Line of Credit Facility [Line Items]
2022				1,300,000
Line of credit \| Silicon Valley Bank
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 35,000,000
Minimum requirement liability				$ 40,000,000
Line of credit \| Silicon Valley Bank \| Secured Debt
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	25,000,000
Periodic payment terms, balloon payment to be paid	1,200,000
Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 10,000,000
Effective interest rate				6.70%
Repayments of long-term debt		$ 12,400,000	$ 12,500,000
LIBOR \| Line of credit \| Silicon Valley Bank \| Secured Debt
Line of Credit Facility [Line Items]
Basis spread on variable rate	4.20%
LIBOR \| Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.50%
Minimum \| LIBOR \| Line of credit \| Silicon Valley Bank \| Secured Debt
Line of Credit Facility [Line Items]
Interest rate, stated percentage	5.43%
Minimum \| LIBOR \| Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Interest rate, stated percentage	4.70%
Debt prepayment tranche one \| LIBOR \| Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Prepayment premium				$ 750,000
Debt prepayment tranche two \| LIBOR \| Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Prepayment premium				500,000
Debt prepayment tranche three \| LIBOR \| Line of credit \| Silicon Valley Bank \| Revolving credit facility
Line of Credit Facility [Line Items]
Prepayment premium				$ 250,000

Debt - Schedule of Loan and Sec

Debt - Schedule of Loan and Security Agreement (Details) - Line of credit - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Debt principal	$ 100	$ 25,000
End-of-term debt obligation	594	365
Unamortized debt issuance costs	0	(83)
Net debt obligation	$ 694	$ 25,282

Debt - Credit Agreement (Detail

Debt - Credit Agreement (Details)	Nov. 03, 2017USD ($)	Mar. 30, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Dec. 31, 2019USD ($)term_loaninstallment	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Debt Instrument [Line Items]
Repayments of long-term debt					$ 24,900,000	$ 0	$ 25,385,000
Prepayment premium					$ 0	$ 0	$ 1,536,000
Visium \| Line of credit
Debt Instrument [Line Items]
Number of term loans (in term loans) \| term_loan					2
Line of credit facility, maximum borrowing capacity					$ 40,000,000
Repayments of long-term debt	$ 27,300,000
Interest rate, stated percentage					12.00%
Number of installments (in installments) \| installment					8
Term of debt with equal quarterly installments					2 years
Prepayment premium					0.240
Fixed rate percentage paid in cash					0.090
Interest paid-in-kind percentage					0.030
Conversion of accrued interest to long-term debt			$ 385,000	$ 385,000
Prepayment premium	$ 1,500,000
Visium \| Line of credit \| Initial Term Loan
Debt Instrument [Line Items]
Proceeds from lines of credit		$ 25,000,000
Repayments of long-term debt		$ 5,000,000

Debt - Interest Expense (Detail

Debt - Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Debt - Interest Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Disclosure [Abstract]
Nominal debt interest	$ 332	$ 1,568	$ 2,838
Amortization and write-off of debt discount and issuance costs	107	57	472
End-of-term debt obligation interest	229	312	53
Debt prepayment penalty	0	0	1,536
Interest on capital lease	9	26	42
Total	$ 677	$ 1,963	$ 4,941

Stockholders' Equity (Details)

Stockholders' Equity (Details)	May 07, 2019USD ($)$ / sharesshares	Jul. 31, 2018USD ($)$ / sharesshares	Dec. 31, 2019USD ($)vote$ / sharesshares	Dec. 31, 2018$ / sharesshares
Common Stock
Common stock, shares authorized			125,000,000	125,000,000
Par value of shares of common stock (in dollars per share) \| $ / shares			$ 0.001	$ 0.001
Number of votes for each share of stock (in votes) \| vote			1
Dividends declared \| $			$ 0
Options issued and outstanding (in shares)			5,562,484	6,235,258
Total number of shares reserved for issuance			7,690,456	8,116,335
Stock issued during the period (in shares)	6,325,000
Sale of stock (in usd per share) \| $ / shares	$ 23.25
Proceeds from issuance of common stock \| $	$ 137,800,000
Payments of stock issuance costs \| $	$ 9,200,000
Number of shares issued in transaction (in shares)		5,750,000
Over-Allotment Option
Common Stock
Stock issued during the period (in shares)	825,000
Payments of stock issuance costs \| $		$ 3,900,000
Number of shares issued in transaction (in shares)		750,000
Proceeds from issuance of common stock \| $		$ 55,000,000
Shares of common stock subject to outstanding options
Common Stock
Options issued and outstanding (in shares)			5,562,484	6,235,258
Shares available for issuance (in shares)			1,954,804	1,571,658
Employee stock purchase plan
Common Stock
Shares available for issuance (in shares)			173,168	309,419
Common Stock \| Over-Allotment Option
Common Stock
Shares issued, price per share (in usd per share) \| $ / shares		$ 10.25

Stock Incentive Plans - Stock O

Stock Incentive Plans - Stock Option Plans (Details) - shares	1 Months Ended	12 Months Ended
	Feb. 29, 2008	Dec. 31, 2019	Oct. 31, 2013
2008 Plan \| ISO \| Minimum
Stock incentive plans
Voting power of person owning stock	10.00%
Option price as a percentage of estimated fair value of shares on date of grant to a person owning stock representing more than 10% of voting power of all classes of stock	110.00%
2008 Plan \| ISO \| Maximum
Stock incentive plans
Term of options granted to a person owning stock representing more than 10% of voting power of all classes of stock	5 years
2008 Plan \| Employee stock options \| Minimum
Stock incentive plans
Minimum purchase price as a percentage of fair market value	100.00%
2008 Plan \| Employee stock options \| Maximum
Stock incentive plans
Term of options granted	10 years
Stock Incentive Plan 2013
Stock incentive plans
Number of additional shares reserved for issuance (in shares)			1,700,000
Maximum annual increase in outstanding shares on the last day of the immediately preceding fiscal year (as a percent)		4.00%
Number of shares available for issuance (in shares)		1,954,799
Stock Incentive Plan 2013 \| ISO \| Maximum
Stock incentive plans
Minimum purchase price as a percentage of fair market value		100.00%
Stock Incentive Plan 2013 \| NSO \| Minimum
Stock incentive plans
Minimum purchase price as a percentage of fair market value		100.00%
Stock Incentive Plan 2013 \| NSO \| Outside director who was not previously an employee
Stock incentive plans
Percentage of award vesting after one year		25.00%
Shares granted as initial grant (in shares)		35,000
Stock Incentive Plan 2013 \| Employee stock options \| Outside director serving as a member of Board of Directors for at least six months
Stock incentive plans
Shares granted as annual grant (in shares)		10,000
Stock Incentive Plan 2013 \| Employee stock options \| Outside director serving as a member of Board of Directors for at least six months \| Minimum
Stock incentive plans
Period for which director has to serve as board of director to receive grant to purchase shares		6 months
Stock Incentive Plan 2013 \| Employee stock options \| Outside director
Stock incentive plans
Minimum purchase price as a percentage of fair market value		100.00%
Stock Incentive Plan 2013 \| Employee stock options \| Outside director \| Maximum
Stock incentive plans
Expiration period after termination of service		12 months
Share-based compensation award, tranche one \| Stock Incentive Plan 2013 \| ISO
Stock incentive plans
Vesting rights, percentage		33.00%
Share-based compensation award, tranche two \| Stock Incentive Plan 2013 \| ISO
Stock incentive plans
Vesting rights, percentage		33.00%
Share-based compensation award, tranche three \| Stock Incentive Plan 2013 \| ISO
Stock incentive plans
Vesting rights, percentage		33.00%

Stock Incentive Plans - Activit

Stock Incentive Plans - Activity Under Stock Option Plans (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Shares Available for Grant
Additional options authorized (in shares)	1,634,528
Canceled (in shares)	180,017
Stock Options Outstanding
Balance at beginning of the period (in shares)	6,235,258
Canceled (in shares)	(180,017)
Exercised (in shares)	(1,846,222)
Balance at the end of the period (in shares)	5,562,484	6,235,258
Options vested and exercisable at the end of the period (in shares)	2,651,858
Options vested and expected to vest at the end of the period (in shares)	4,442,275
Weighted Average Exercise Price
Balance at beginning of the period (in dollars per share)	$ 7.95
Canceled (in dollars per share)	9.40
Exercised (in dollars per share)	7.77
Balance at the end of the period (in dollars per share)	10.66	$ 7.95
Options vested and exercisable at the end of the period (in dollars per share)	8.13
Options vested and expected to vest at the end of the period (in dollars per share)	$ 10.48
Weighted Average Remaining Contractual Life
Balance	6 years 11 months 19 days	6 years 11 months 12 days
Options vested and exercisable at the end of the period	5 years 10 months 24 days
Options vested and expected to vest at the end of the period	6 years 10 months 28 days
Aggregate Intrinsic Value
Balance (in dollars)	$ 79,760	$ 27,340
Options vested and exercisable at the end of the period (in dollars)	52,469
Options vested and expected to vest at the end of the period (in dollars)	$ 77,453
Employee stock options
Shares Available for Grant
Granted (in shares)	(969,500)
Stock Options Outstanding
Granted (in shares)	969,500
Weighted Average Exercise Price
Granted (in dollars per share)	$ 21.16
Restricted stock units
Shares Available for Grant
Granted (in shares)	(505,965)
Tax portion of restricted stock units vested (in shares)	44,066
Stock Options Outstanding
Granted (in shares)	505,965
Vested (in shares)	(122,000)
Aggregate Intrinsic Value
Options vested and expected to vest at the end of the period (in dollars)	$ 2,720	$ 184
Shares of common stock subject to outstanding options
Shares Available for Grant
Balance at the beginning of the period (in shares)	1,571,658
Balance at the end of the period (in shares)	1,954,804	1,571,658
Stock Options Outstanding
Balance at beginning of the period (in shares)	6,235,258
Balance at the end of the period (in shares)	5,562,484	6,235,258

Stock Incentive Plans - Additio

Stock Incentive Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock incentive plans
Weighted average fair value of options to purchase common stock granted (in dollars per share)	$ 11.07	$ 3.62	$ 4.49
Intrinsic value of stock options exercised (in dollars)	$ 31,300	$ 4,900	$ 700
Weighted average grant date fair value (in dollars per share)	$ 21.90	$ 6.17
Intrinsic value of stock options outstanding	$ 77,453
Options outstanding (in shares)	5,562,484	6,235,258
Common Stock
Stock incentive plans
Share price (in dollars per share)	$ 27.92	$ 12.58
Non Employee Stock Option
Stock incentive plans
Options outstanding (in shares)	0
Employee stock options
Stock incentive plans
Total estimated grant date fair value of options to purchase common stock vested (in dollars)	$ 4,400	$ 4,100	$ 3,100
Restricted stock units
Stock incentive plans
Intrinsic value of stock options outstanding	$ 2,720	$ 184

Stock Incentive Plans Stock Inc

Stock Incentive Plans Stock Incentive Plans - ESPP (Details) - Employee stock purchase plan	12 Months Ended
	Dec. 31, 2019USD ($)
Stock incentive plans
Maximum offering period	12 months
Purchase period	6 months
Maximum fair market value of shares an employee can purchase per calendar year	$ 25,000
Minimum
Stock incentive plans
Minimum purchase price as a percentage of fair market value	85.00%

Stock Incentive Plans - Stock-b

Stock Incentive Plans - Stock-based Compensation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-based compensation
Share-based compensation expense (in dollars)	$ 9,807	$ 5,958	$ 6,617
Cost of testing revenue
Stock-based compensation
Share-based compensation expense (in dollars)	277	130	133
Research and development
Stock-based compensation
Share-based compensation expense (in dollars)	1,856	1,018	1,495
Selling and marketing
Stock-based compensation
Share-based compensation expense (in dollars)	2,938	1,866	1,899
General and administrative
Stock-based compensation
Share-based compensation expense (in dollars)	4,736	$ 2,944	$ 3,090
Stock-based Compensation
Stock-based compensation
Unrecognized compensation expense (in dollars)	$ 18,400
Period over which unrecognized compensation expense expected to be recognized	2 years 2 months 12 days
Stock-based Compensation, employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average volatility, low end of range (as a percent)	52.90%	50.40%	50.40%
Weighted-average volatility, high end of range (as a percent)	53.40%	52.70%	52.40%
Risk-free interest rate, low end of range (as a percent)	1.90%	2.40%	1.80%
Risk-free interest rate, high end of range (as a percent)	2.60%	3.10%	2.33%
Stock-based Compensation, non-employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average volatility, low end of range (as a percent)	0.00%	43.60%	50.40%
Weighted-average volatility, high end of range (as a percent)	0.00%	50.50%	51.10%
Risk-free interest rate, low end of range (as a percent)	0.00%	1.84%	2.16%
Risk-free interest rate, high end of range (as a percent)	0.00%	2.87%	2.37%
Employee stock purchase plan
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average volatility, low end of range (as a percent)	53.38%	42.88%	37.00%
Weighted-average volatility, high end of range (as a percent)	71.77%	47.74%	43.86%
Risk-free interest rate, low end of range (as a percent)	1.88%	1.64%	0.65%
Risk-free interest rate, high end of range (as a percent)	2.56%	2.45%	1.22%
Minimum \| Stock-based Compensation, employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	5 years 6 months	5 years 6 months	5 years 6 months
Minimum \| Stock-based Compensation, non-employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	0 years	3 months	6 years 9 months 18 days
Minimum \| Employee stock purchase plan
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	6 months	6 months	6 months
Maximum \| Stock-based Compensation, employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	6 years 29 days	6 years 29 days	6 years 29 days
Maximum \| Stock-based Compensation, non-employees
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	0 years	6 years 9 months	7 years 9 months
Maximum \| Employee stock purchase plan
Assumptions used to calculate estimated fair value of stock options using the Black-Scholes option-pricing valuation model
Weighted-average expected term	1 year	1 year	1 year

Thyroid Cytopathology Partners

Thyroid Cytopathology Partners (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Thyroid Cytopathology Partners
Thyroid Cytopathology Partners
Reduction to rent expense for TCP's portion of costs for shared space	$ 11	$ 128	$ 114

Income Taxes - Additional Infor

Income Taxes - Additional Information (Details) - USD ($)	12 Months Ended
Income Taxes - Additional Information (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Pretax loss	$ 12,500,000	$ 23,000,000	$ 31,000,000
Income tax expense (benefit)	0	0	0
Increase (decrease) in valuation allowance against deferred tax assets	9,900,000	3,700,000	(14,300,000)
Share-based compensation excess tax benefit amount	(628,000)	0	0
Operating loss carryforwards
Unrecognized tax benefits	3,278,000	$ 2,799,000	$ 2,523,000	$ 2,222,000
Federal
Operating loss carryforwards
Net operating loss carryforwards	236,900,000
Tax credit carryforward	4,900,000
State
Operating loss carryforwards
Tax credit carryforward	4,700,000
State \| California
Operating loss carryforwards
Net operating loss carryforwards	58,300,000
State \| Other state income tax purposes
Operating loss carryforwards
Net operating loss carryforwards	$ 45,200,000

Income Taxes - Tax Provision (D

Income Taxes - Tax Provision (Details) - USD ($)	12 Months Ended
Income Taxes - Tax Provision (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of tax expense computed at the statutory federal rate and the Company's tax expense
U.S. federal taxes at statutory rate	$ (2,632,000)	$ (4,825,000)	$ (10,541,000)
State tax (net of federal benefit)	(828,000)	0	15,000
Non deductible officers' compensation	439,000	409,000	0
Stock based compensation - PSU/RSU/NQSQ	628,000	0	0
Permanent differences	221,000	285,000	198,000
Incentive stock options	(4,994,000)	(256,000)	994,000
Tax credits	(996,000)	(777,000)	(588,000)
Change in valuation allowance	8,162,000	5,164,000	(14,552,000)
Rate differential impact - Tax Cuts and Jobs Act	0	0	24,474,000
Total	$ 0	$ 0	$ 0

Income Taxes - Deferred Tax Ass

Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 56,506	$ 50,410	$ 47,177
Research and development credits	5,579	4,584	4,034
Stock-based compensation	2,246	1,032	2,068
NanoString intangibles and goodwill	380	0	0
Operating lease liability	3,068	0	0
Accruals and other	2,610	2,918	2,375
Gross deferred tax assets	70,389	58,944	55,654
Valuation allowance	(65,228)	(55,366)	(51,657)
Net deferred tax assets	5,161	3,578	3,997
Deferred tax liabilities:
Property and equipment	(471)	(695)	(983)
In-process research and development	(2,597)	(2,883)	(3,014)
ROU assets	(2,093)	0	0
Gross deferred tax liabilities	(5,161)	(3,578)	(3,997)
Net deferred tax liabilities	(5,161)	(3,578)	(3,997)
Net deferred taxes	$ 0	$ 0	$ 0

Income Taxes - Uncertain Tax Po

Income Taxes - Uncertain Tax Positions (Details) - USD ($)	12 Months Ended
Income Taxes - Uncertain Tax Positions (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of the beginning and ending amount of unrecognized tax benefits
Unrecognized tax benefits, beginning of period	$ 2,799,000	$ 2,523,000	$ 2,222,000
Gross increases—tax position in prior period	0	0	0
Gross decreases—tax position in prior period	0	(97,000)	0
Gross increases—current period tax position	479,000	373,000	301,000
Lapse of statute of limitations	0	0	0
Unrecognized tax benefits, end of period	3,278,000	$ 2,799,000	$ 2,523,000
Interest expense or penalties related to unrecognized tax benefits	$ 0

Income Taxes - Income Tax Exami

Income Taxes - Income Tax Examination (Details)	12 Months Ended
Income Taxes - Income Tax Examination (Details)	Dec. 31, 2019
Federal
Income tax examination
Income tax examination period	3 years
State
Income tax examination
Income tax examination period	4 years

401(k) Plan (Details)

401(k) Plan (Details) - USD ($) $ in Thousands	12 Months Ended
401(k) Plan (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Employer contributions to the plan	$ 509	$ 448	$ 324

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Selected Quarterly Financial Data (Unaudited)
Total revenue	$ 29,730	$ 30,973	$ 30,136	$ 29,529	$ 25,750	$ 23,466	$ 22,751	$ 20,041	$ 120,368	$ 92,008	$ 71,953
Net loss	$ (7,458)	$ (730)	$ (2,494)	$ (1,917)	$ (3,105)	$ (4,469)	$ (6,248)	$ (9,177)	$ (12,599)	$ (22,999)	$ (31,003)
Net loss per common share, basic and diluted (in dollars per share)	$ (0.15)	$ (0.02)	$ (0.05)	$ (0.05)	$ (0.08)	$ (0.12)	$ (0.18)	$ (0.27)	$ (0.27)	$ (0.62)	$ (0.91)
Shares use to compute net loss per common share, basic and diluted (in shares)	49,095,703	48,588,296	45,586,081	41,168,593	40,731,334	38,620,036	34,314,234	34,271,254	46,138,177	37,020,246	33,925,617