BlackRock Taxable Municipal Bond Trust (BBN) N-CSRS4 Sep 24Certified semi-annual shareholder report (management investment company)Financial data

Company Profile

N-2

N-2 - $ / shares	6 Months Ended
N-2 - $ / shares	Jun. 30, 2024	Dec. 31, 2023
Cover [Abstract]
Entity Central Index Key	0001493683
Amendment Flag	false
Document Type	N-CSRS
Entity Registrant Name	BlackRock Taxable Municipal Bond Trust
General Description of Registrant [Abstract]
Investment Objectives and Practices [Text Block]	Investment Objective BlackRock Taxable Municipal Bond Trust ’ s (BBN) (the “Trust”) primary investment objective is to seek high current income, with a secondary objective of capital appreciation. The Trust seeks to achieve its investment objectives by investing primarily in a portfolio of taxable municipal securities, including Build America Bonds (“BABs”), issued by state and local governments to finance capital projects such as public schools, roads, transportation infrastructure, bridges, ports and public buildings. The Trust originally sought to achieve its investment objectives by investing primarily in a portfolio of BABs, which are taxable municipal securities issued pursuant to the American Recovery and Reinvestment Act of 2009. Given the uncertainty around the BABs program at the time of the Trust’s launch in 2010, the Trust’s initial public offering prospectus included a Contingent Review Provision. For any 24-month period, if there were no new issuances of BABs or other analogous taxable municipal securities, the Board of Trustees (the “Board”) would undertake an evaluation of potential actions with respect to the Trust. Under the Contingent Review Provision, such potential action may include changes to the Trust’s non-fundamental investment policies to broaden its primary investment focus to include taxable municipal securities generally. The BABs program expired on December 31, 2010 and was not renewed. Accordingly, there have been no new issuances of BABs since that date. Pursuant to the Contingent Review Provision, on June 12, 2015, the Board approved a proposal to amend the Trust’s investment policy from “Under normal market conditions, the Trust invests at least 80% of its managed assets in BABs” to “Under normal market conditions, the Trust invests at least 80% of its managed assets in taxable municipal securities, which include BABs”, and to change the name of the Trust from “BlackRock Build America Bond Trust” to “BlackRock Taxable Municipal Bond Trust.” These changes became effective on August 25, 2015. The Trust continues to maintain its other investment policies, including its ability to invest up to 20% of its managed assets in securities other than taxable municipal securities. Such other securities may include tax-exempt securities, U.S. Treasury securities, obligations of the U.S. Government, its agencies and instrumentalities and corporate bonds issued by issuers that have, in BlackRock Advisors, LLC ’ s (the "Manager") view, typically been associated with or sold in the municipal market. Bonds issued by private universities and hospitals, or bonds sold to finance military housing developments are examples of such securities. The Trust also continues to invest at least 80% of its managed assets in securities that at the time of purchase are investment grade quality. As used herein, “managed assets” means the total assets of the Trust (including any assets attributable to money borrowed for investment purposes) minus the sum of the Trust’s accrued liabilities (other than money borrowed for investment purposes). As of June 30, 2024, 48% of the Trust’s portfolio is composed of BABs. Like other taxable municipal securities, interest received on BABs is subject to U.S. tax and may be subject to state income tax. Issuers of direct pay BABs, however, are eligible to receive a subsidy from the U.S. Treasury of up to 35% of the interest paid on the BABs. This allowed such issuers to issue bonds that pay interest rates that were expected to be competitive with the rates typically paid by private bond issuers in the taxable fixed income market. While the U.S. Treasury subsidizes the interest paid on BABs, it does not guarantee the principal or interest payments on BABs, and there is no guarantee that the U.S. Treasury will not reduce or eliminate the subsidy for BABs in the future. Any interruption, delay, reduction and/or offset of the reimbursement from the U.S. Treasury may reduce the demand for direct pay BABs and/or potentially trigger extraordinary call features of the BABs. As of the date of this report, the subsidy that issuers of direct pay BABs receive from the U.S. Treasury has been reduced from its original level as the result of budgetary sequestration. The extraordinary call features of some BABs permit early redemption at par value, and the reduction in the subsidy issuers of direct pay BABs receive from the U.S. Treasury has resulted, and may continue to result, in early redemptions of some BABs at par value. Such early redemptions at par value may result in a potential loss in value for investors of such BABs, who may have purchased the securities at prices above par, and may require such investors to reinvest redemption proceeds in lower-yielding securities. As of the date of this report, the Trust did not own any BABs subject to a par value extraordinary call feature. Additionally, many BABs also have more typical call provisions that permit early redemption at a stated spread to an applicable prevailing U.S. Treasury rate. Early redemptions in accordance with these call provisions may likewise result in potential losses for the Trust and give rise to reinvestment risk, which could reduce the Trust’s income and distributions. No assurance can be given that the Trust’s investment objective will be achieved.
Risk Factors [Table Text Block]	9. PRINCIPAL RISKS In the normal course of business, the Trust invests in securities or other instruments and may enter into certain transactions, and such activities subject the Trust to various risks, including among others, fluctuations in the market (market risk) or failure of an issuer to meet all of its obligations. The value of securities or other instruments may also be affected by various factors, including, without limitation: (i) the general economy; (ii) the overall market as well as local, regional or global political and/or social instability; (iii) regulation, taxation or international tax treaties between various countries; or (iv) currency, interest rate and price fluctuations. Local, regional or global events such as war, acts of terrorism, the spread of infectious illness or other public health issues, recessions, or other events could have a significant impact on the Trust and its investments. The Trust may hold a significant amount of bonds subject to calls by the issuers at defined dates and prices. When bonds are called by issuers and the Trust reinvests the proceeds received, such investments may be in securities with lower yields than the bonds originally held, and correspondingly, could adversely impact the yield and total return performance of the Trust. The Build America Bonds (“BABs”) market is smaller, less diverse and less liquid than other types of municipal securities. Since the BABs program expired on December 31, 2010 and was not extended, BABs may be less actively traded, which may negatively affect the value of BABs held by the Trust. The Trust may invest in BABs. Issuers of direct pay BABs held in the Trust’s portfolio receive a subsidy from the U.S. Treasury with respect to interest payment on bonds. There is no assurance that an issuer will comply with the requirements to receive such subsidy or that such subsidy will not be reduced or terminated altogether in the future. As of period end, the subsidy that issuers of direct payment BABs receive from the U.S. Treasury has been reduced as the result of budgetary sequestration, which has resulted, and which may continue to result, in early redemptions of BABs at par value. The early redemption of BABs at par value may result in a potential loss in value for investors of such BABs, including the Trust, who may have purchased the securities at prices above par, and may require the Trust to reinvest redemption proceeds in lower-yielding securities which could reduce the Trust’s income and distributions. Moreover, the elimination or reduction in subsidy from the federal government may adversely affect an issuer’s ability to repay or refinance BABs and the BABs’ credit ratings, which, in turn, may adversely affect the value of the BABs held by the Trust and the Trust’s NAV. Illiquidity Risk: The Trust may invest without limitation in illiquid or less liquid investments or investments in which no secondary market is readily available or which are otherwise illiquid, including private placement securities. The Trust may not be able to readily dispose of such investments at prices that approximate those at which the Trust could sell such investments if they were more widely traded and, as a result of such illiquidity, the Trust may have to sell other investments or engage in borrowing transactions if necessary to raise funds to meet its obligations. Limited liquidity can also affect the market price of investments, thereby adversely affecting the Trust’s NAV and ability to make dividend distributions. Privately issued debt securities are often of below investment grade quality, frequently are unrated and present many of the same risks as investing in below investment grade public debt securities. Market Risk: The Trust may be exposed to prepayment risk, which is the risk that borrowers may exercise their option to prepay principal earlier than scheduled during periods of declining interest rates, which would force the Trust to reinvest in lower yielding securities. The Trust may also be exposed to reinvestment risk, which is the risk that income from the Trust’s portfolio will decline if the Trust invests the proceeds from matured, traded or called fixed-income securities at market interest rates that are below the Trust portfolio’s current earnings rate. Municipal securities are subject to the risk that litigation, legislation or other political events, local business or economic conditions, credit rating downgrades, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest or otherwise affect the value of such securities. Municipal securities can be significantly affected by political or economic changes, including changes made in the law after issuance of the securities, as well as uncertainties in the municipal market related to, taxation, legislative changes or the rights of municipal security holders, including in connection with an issuer insolvency. Municipal securities backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the discontinuance of the tax benefits supporting the project or assets or the inability to collect revenues for the project or from the assets. Municipal securities may be less liquid than taxable bonds, and there may be less publicly available information on the financial condition of municipal security issuers than for issuers of other securities. Counterparty Credit Risk: The Trust may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions, including making timely interest and/or principal payments or otherwise honoring its obligations. The Trust manages counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Trust to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Trust ’ s exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statement of Assets and Liabilities, less any collateral held by the Trust. A derivative contract may suffer a mark-to-market loss if the value of the contract decreases due to an unfavorable change in the market rates or values of the underlying instrument. Losses can also occur if the counterparty does not perform under the contract. With exchange-traded futures, there is less counterparty credit risk to the Trust since the exchange or clearinghouse, as counterparty to such instruments, guarantees against a possible default. The clearinghouse stands between the buyer and the seller of the contract; therefore, credit risk is limited to failure of the clearinghouse. While offset rights may exist under applicable law, the Trust does not have a contractual right of offset against a clearing broker or clearinghouse in the event of a default (including the bankruptcy or insolvency). Additionally, credit risk exists in exchange-traded futures with respect to initial and variation margin that is held in a clearing broker’s customer accounts. While clearing brokers are required to segregate customer margin from their own assets, in the event that a clearing broker becomes insolvent or goes into bankruptcy and at that time there is a shortfall in the aggregate amount of margin held by the clearing broker for all its clients, typically the shortfall would be allocated on a pro rata basis across all the clearing broker’s customers, potentially resulting in losses to the Trust. Geographic/Asset Class Risk: A diversified portfolio, where this is appropriate and consistent with a fund’s objectives, minimizes the risk that a price change of a particular investment will have a material impact on the NAV of a fund. The investment concentrations within the Trust’s portfolio are disclosed in its Schedule of Investments. The Trust invests a significant portion of its assets in securities within a single or limited number of market sectors. When a fund concentrates its investments in this manner, it assumes the risk that economic, regulatory, political and social conditions affecting such sectors may have a significant impact on the Trust and could affect the income from, or the value or liquidity of, the Trust’s portfolio. Investment percentages in specific sectors are presented in the Schedule of Investments. The Trust invests a significant portion of its assets in fixed-income securities and/or uses derivatives tied to the fixed-income markets. Changes in market interest rates or economic conditions may affect the value and/or liquidity of such investments. Interest rate risk is the risk that prices of bonds and other fixed-income securities will decrease as interest rates rise and increase as interest rates fall. The Trust may be subject to a greater risk of rising interest rates during a period of historically low interest rates. The Federal Reserve has raised the federal funds rate as part of its efforts to address inflation. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility, and could negatively impact the Trust ’ s performance. The Trust invests a significant portion of its assets in securities of issuers located in the United States. A decrease in imports or exports, changes in trade regulations, inflation and/or an economic recession in the United States may have a material adverse effect on the U.S. economy and the securities listed on U.S. exchanges. Proposed and adopted policy and legislative changes in the United States may also have a significant effect on U.S. markets generally, as well as on the value of certain securities. Governmental agencies project that the United States will continue to maintain elevated public debt levels for the foreseeable future which may constrain future economic growth. Circumstances could arise that could prevent the timely payment of interest or principal on U.S. government debt, such as reaching the legislative “debt ceiling.” Such non-payment would result in substantial negative consequences for the U.S. economy and the global financial system. If U.S. relations with certain countries deteriorate, it could adversely affect issuers that rely on the United States for trade. The United States has also experienced increased internal unrest and discord. If these trends were to continue, they may have an adverse impact on the U.S. economy and the issuers in which the Trust invests.
Share Price [Table Text Block]	Market Price and Net Asset Value Per Share Summary 06/30/24 12/31/23 Change High Low Closing Market Price $ 16.35 $ 16.26 0.55 % $ 17.11 $ 15.47 Net Asset Value 17.46 18.07 (3.38 ) 18.29 16.95
Lowest Price or Bid	$ 15.47
Highest Price or Bid	17.11
Lowest Price or Bid, NAV	16.95
Highest Price or Bid, NAV	18.29
Share Price	16.35	$ 16.26
NAV Per Share	$ 17.46	$ 18.07
Capital Stock, Long-Term Debt, and Other Securities [Abstract]
Capital Stock [Table Text Block]	10. CAPITAL SHARE TRANSACTIONS The Trust is authorized to issue an unlimited number of shares, all of which were initially classified as Common Shares. The par value for the Trust’s Common Shares is $0.001. The Board is authorized, however, to reclassify any unissued Common Shares to Preferred Shares without the approval of Common Shareholders. Common Shares For the six months ended June 30, 2024, shares issued and outstanding remained constant. For the year ended December 31, 2023, shares issued and outstanding increased by 5,932 as a result of Shelf Offering. The Trust participates in an open market share repurchase program (the “Repurchase Program”). From December 1, 2023 through November 30, 2024, the Trust may repurchase up to 5% of its outstanding common shares under the Repurchase Program, based on common shares outstanding as of the close of business on November 30, 2023, subject to certain conditions. The Repurchase Program has an accretive effect as shares are purchased at a discount to the Trust’s NAV. There is no assurance that the Trust will purchase shares in any particular amounts. For the six months ended June 30, 2024, the Trust did not repurchase any shares. BBN filed a prospectus with the U.S. Securities and Exchange Commission (“SEC”) allowing it to issue an additional 20,000,000 Common Shares, through an equity Shelf Offering. During the six months ended June 30, 2024, BBN did not issue any Common Shares through its Shelf Offering. Effective February 10, 2024, BBN is no longer actively engaged in a Shelf Offering and has no effective registration statement or current prospectus for the sale of Common Shares. Initial costs incurred by BBN in connection with its Shelf Offering were recorded as “Deferred offering costs” in the Statement of Assets and Liabilities. As shares were sold, a portion of the costs attributable to the shares sold were charged against paid-in-capital. Any remaining deferred charges at the end of the Shelf Offering period were charged to expense.
Outstanding Securities [Table Text Block]	The Trust is authorized to issue an unlimited number of shares, all of which were initially classified as Common Shares.
Outstanding Security, Held [Shares]	61,792,514
Illiquidity Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]	Illiquidity Risk: The Trust may invest without limitation in illiquid or less liquid investments or investments in which no secondary market is readily available or which are otherwise illiquid, including private placement securities. The Trust may not be able to readily dispose of such investments at prices that approximate those at which the Trust could sell such investments if they were more widely traded and, as a result of such illiquidity, the Trust may have to sell other investments or engage in borrowing transactions if necessary to raise funds to meet its obligations. Limited liquidity can also affect the market price of investments, thereby adversely affecting the Trust’s NAV and ability to make dividend distributions. Privately issued debt securities are often of below investment grade quality, frequently are unrated and present many of the same risks as investing in below investment grade public debt securities.
Market Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]	Market Risk: The Trust may be exposed to prepayment risk, which is the risk that borrowers may exercise their option to prepay principal earlier than scheduled during periods of declining interest rates, which would force the Trust to reinvest in lower yielding securities. The Trust may also be exposed to reinvestment risk, which is the risk that income from the Trust’s portfolio will decline if the Trust invests the proceeds from matured, traded or called fixed-income securities at market interest rates that are below the Trust portfolio’s current earnings rate. Municipal securities are subject to the risk that litigation, legislation or other political events, local business or economic conditions, credit rating downgrades, or the bankruptcy of the issuer could have a significant effect on an issuer’s ability to make payments of principal and/or interest or otherwise affect the value of such securities. Municipal securities can be significantly affected by political or economic changes, including changes made in the law after issuance of the securities, as well as uncertainties in the municipal market related to, taxation, legislative changes or the rights of municipal security holders, including in connection with an issuer insolvency. Municipal securities backed by current or anticipated revenues from a specific project or specific assets can be negatively affected by the discontinuance of the tax benefits supporting the project or assets or the inability to collect revenues for the project or from the assets. Municipal securities may be less liquid than taxable bonds, and there may be less publicly available information on the financial condition of municipal security issuers than for issuers of other securities.
Counterparty Credit Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]	Counterparty Credit Risk: The Trust may be exposed to counterparty credit risk, or the risk that an entity may fail to or be unable to perform on its commitments related to unsettled or open transactions, including making timely interest and/or principal payments or otherwise honoring its obligations. The Trust manages counterparty credit risk by entering into transactions only with counterparties that the Manager believes have the financial resources to honor their obligations and by monitoring the financial stability of those counterparties. Financial assets, which potentially expose the Trust to market, issuer and counterparty credit risks, consist principally of financial instruments and receivables due from counterparties. The extent of the Trust ’ s exposure to market, issuer and counterparty credit risks with respect to these financial assets is approximately their value recorded in the Statement of Assets and Liabilities, less any collateral held by the Trust. A derivative contract may suffer a mark-to-market loss if the value of the contract decreases due to an unfavorable change in the market rates or values of the underlying instrument. Losses can also occur if the counterparty does not perform under the contract. With exchange-traded futures, there is less counterparty credit risk to the Trust since the exchange or clearinghouse, as counterparty to such instruments, guarantees against a possible default. The clearinghouse stands between the buyer and the seller of the contract; therefore, credit risk is limited to failure of the clearinghouse. While offset rights may exist under applicable law, the Trust does not have a contractual right of offset against a clearing broker or clearinghouse in the event of a default (including the bankruptcy or insolvency). Additionally, credit risk exists in exchange-traded futures with respect to initial and variation margin that is held in a clearing broker’s customer accounts. While clearing brokers are required to segregate customer margin from their own assets, in the event that a clearing broker becomes insolvent or goes into bankruptcy and at that time there is a shortfall in the aggregate amount of margin held by the clearing broker for all its clients, typically the shortfall would be allocated on a pro rata basis across all the clearing broker’s customers, potentially resulting in losses to the Trust.
Geographic Asset Class Risk [Member]
General Description of Registrant [Abstract]
Risk [Text Block]	Geographic/Asset Class Risk: A diversified portfolio, where this is appropriate and consistent with a fund’s objectives, minimizes the risk that a price change of a particular investment will have a material impact on the NAV of a fund. The investment concentrations within the Trust’s portfolio are disclosed in its Schedule of Investments. The Trust invests a significant portion of its assets in securities within a single or limited number of market sectors. When a fund concentrates its investments in this manner, it assumes the risk that economic, regulatory, political and social conditions affecting such sectors may have a significant impact on the Trust and could affect the income from, or the value or liquidity of, the Trust’s portfolio. Investment percentages in specific sectors are presented in the Schedule of Investments. The Trust invests a significant portion of its assets in fixed-income securities and/or uses derivatives tied to the fixed-income markets. Changes in market interest rates or economic conditions may affect the value and/or liquidity of such investments. Interest rate risk is the risk that prices of bonds and other fixed-income securities will decrease as interest rates rise and increase as interest rates fall. The Trust may be subject to a greater risk of rising interest rates during a period of historically low interest rates. The Federal Reserve has raised the federal funds rate as part of its efforts to address inflation. Changing interest rates may have unpredictable effects on markets, may result in heightened market volatility, and could negatively impact the Trust ’ s performance. The Trust invests a significant portion of its assets in securities of issuers located in the United States. A decrease in imports or exports, changes in trade regulations, inflation and/or an economic recession in the United States may have a material adverse effect on the U.S. economy and the securities listed on U.S. exchanges. Proposed and adopted policy and legislative changes in the United States may also have a significant effect on U.S. markets generally, as well as on the value of certain securities. Governmental agencies project that the United States will continue to maintain elevated public debt levels for the foreseeable future which may constrain future economic growth. Circumstances could arise that could prevent the timely payment of interest or principal on U.S. government debt, such as reaching the legislative “debt ceiling.” Such non-payment would result in substantial negative consequences for the U.S. economy and the global financial system. If U.S. relations with certain countries deteriorate, it could adversely affect issuers that rely on the United States for trade. The United States has also experienced increased internal unrest and discord. If these trends were to continue, they may have an adverse impact on the U.S. economy and the issuers in which the Trust invests.