Preferred Stock
Our board of directors is authorized to issue shares of preferred stock in one or more series without stockholder approval. Our board of directors has the discretion to determine the rights, preferences, privileges and restrictions, including voting rights, dividend rights, conversion rights, redemption privileges and liquidation preferences, of each series of preferred stock.
The purpose of authorizing our board of directors to issue preferred stock and determine its rights and preferences is to eliminate delays associated with a stockholder vote on specific issuances. The issuance of preferred stock, while providing flexibility in connection with possible acquisitions, future financings and other corporate purposes, could have the effect of making it more difficult for a third party to acquire, or could discourage a third party from seeking to acquire, a majority of our outstanding voting stock.
Options
As of September 30, 2018, options to purchase an aggregate of 7,248,198shares of our common stock were outstanding under our 2014 equity compensation plan.
Warrants
Follow-On Offerings.In July 2016, in connection with an underwrittenfollow-on offering, we issued warrants to purchase 14,000,000 shares of common stock at an exercise price of $3.00 per share, which expire on July 27, 2021. As of September 30, 2018, there were an aggregate of 14,000,000 shares of common stock underlying these warrants. In July 2017, in connection with an underwrittenfollow-on offering, we issued warrants to purchase 16,000,000 shares of our common stock at an exercise price of $1.55 per share, which expire on July 25, 2022. As of September 30, 2018, there were an aggregate of 15,996,450shares of common stock underlying these warrants.
PIPE Warrants. In June 2015, in connection with a private placement of securities to institutional investors, the placement agents received warrants to purchase shares of common stock at an exercise price of $4.65 per share, which expire on June 11, 2020. As of September 30, 2018, there were an aggregate of189,126 shares of common stock underlying these warrants.
IPO Warrant. In August 2014, we closed our initial public offering. In connection with the initial public offering, The Maxim Group, LLC received a warrant to purchase 206,410 shares of common stock at an exercise price of $7.50 per share, which expires on July 28, 2019. As of September 30, 2018, there were an aggregate of206,410 shares of common stock underlying these warrants.
Note Warrants. We issued approximately $15.0 million in aggregate principal amount of our 8.00% Convertible Notes due May 31, 2015 from June 2013 through June 2014. Each purchaser of the convertible notes received a warrant. As of September 30, 2018, there were 692,858 shares of common stock underlying these warrants at an exercise price of $3.00 per share, each of which expires five years from its respective date of issuance.
Other Warrants. In addition to the foregoing, as of September 30, 2018, we had an aggregate of 180,338 shares of common stock underlying outstanding warrants at a weighted average exercise price of $5.66 per share.
Registration Rights
The shares of common stock underlying the warrants issued in connection with our IPO are currently registered under a registration statement that has been declared effective by the Securities and Exchange Commission, pursuant to registration rights granted to the holders in accordance with the terms of the warrants.
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