DESCRIPTION OF CAPITAL STOCK
General
The following description of common stock and preferred stock, together with the additional information we include in any applicable prospectus supplements or related free writing prospectuses, summarizes the material terms and provisions of the common stock and preferred stock that we may offer under this prospectus but is not complete. For the complete terms of our common stock and preferred stock, please refer to our articles of incorporation, as the same may be amended from time to time, any certificates of determination for our preferred stock, and our bylaws, as amended from time to time. For directions on obtaining these documents, please refer to “Where You Can Find More Information” in this prospectus. The California General Corporation Law, or CGCL, may also affect the terms of these securities. While the terms we have summarized below will apply generally to any future common stock, preferred stock or warrants that we may offer, we will describe the particular terms of any series of these securities in more detail in the applicable prospectus supplement. If we so indicate in a prospectus supplement, the terms of any securities we offer under that prospectus supplement may differ from the terms we describe below.
As of the date of this prospectus, our authorized capital stock consisted of 50,000,000 shares of common stock, no par value per share, and 20,000,000 shares of preferred stock, no par value per share, of which 3,000 shares are designated Series G Convertible Preferred Stock. Our board of directors may establish the rights and preferences of the preferred stock from time to time. As of June 27, 2019, there were approximately 34,194,107 shares of our common stock outstanding and 225 shares of our Series G convertible preferred stock outstanding. Our Series G convertible preferred stock will not be offered under this prospectus.
As of June 27, 2019, we had outstanding options to acquire 1,101,636 shares of our common stock with a weighted average exercise price of $3.24 per share. In addition, as of June 27, 2019 there were warrants outstanding for the purchase of an aggregate of 7,712,225 shares of common stock with a weighted average exercise price of $1.37 per share.
As of June 27, 2019, we have outstanding restricted stock units (RSUs) covering a total of 1,347,062 shares of our common stock. The shares subject to the RSUs vest based upon a vesting price equal to the volume weighted average trading price of our common stock over sixty-five consecutive trading days. Subject to a minimum service period in certain grants, as described in the next sentence, the RSU shares vest as to (i) 134,706 shares on the date the vesting price equals or exceeds $5.00 per share (ii) 404,119 shares the date the vesting price equals or exceeds $10.00 per share and (ii) 808,237 shares the date the vesting price equals or exceeds $15.00 per share. In certain RSUs, vesting occurs the later of the one-year anniversary of the grant and the date the shares reach the vesting price indicated in the preceding sentence.
Common Stock
We may issue shares of our common stock from time to time. Subject to preferences that may be applicable to any outstanding preferred stock, the holders of common stock are entitled to receive ratably dividends, if any, as may be declared from time to time by the board of directors out of funds legally available for that purpose. In the event of our liquidation, dissolution or winding up, whether voluntary or involuntary, the holders of common stock are entitled to share ratably in all assets remaining after payment of liabilities, subject to prior distribution rights of preferred stock, if any, then outstanding. The common stock has no preemptive or conversion rights or other subscription rights. There are no redemption or sinking fund provisions applicable to the common stock. All outstanding shares of common stock are fully paid and nonassessable, and the shares of common stock to be issued upon the closing of this offering will be fully paid and nonassessable.
The holders of common stock are entitled to one vote per share on all matters to be voted upon by the shareholders. So long as the Company continues to be a “listed corporation” as defined in Section 301.5(d) of the California General Corporation Law, the holders of our common stock may not cumulate their votes for the election of directors. The rights and privileges of holders of common stock are subject to, and may be adversely affected by, the rights of holders of shares of preferred stock that we may designate and issue in the future. Our common stock is currently listed on the Nasdaq Capital Market under the symbol “RIBT.”
Preferred Stock
Our articles of incorporation provide that the Board is authorized, without further action by the shareholders (unless such shareholder action is required by applicable law or the rules of any stock exchange or market on