Warrants

3 Months Ended

Mar. 31, 2020

Proceeds From Issuance Of Preferred Stock Preference Stock And Warrants [Abstract]

Warrants

Note 12. Warrants

In connection with certain of its redeemable convertible preferred stock issuances, convertible debt financings and other financing arrangements, the Company has issued warrants for shares of its common stock and various issues of its redeemable convertible preferred stock which have since been converted to common stock warrants.

In September 2019, in connection with the Securities Purchase Agreement (see Note 13), the Company issued and sold an aggregate of 5,411,687 pre-funded warrants exercisable for an aggregate of 5,411,687 shares of common stock. The total exercise price of the pre-funded warrants is $0.65 per share, $0.64 of which was pre-funded and paid to the Company upon issuance of the pre-funded warrants. The remaining exercise price of the pre-funded warrants is $0.01 per share. In March 2020, 3,176,762 of the pre-funded warrants were exercised for proceeds of $31,768. As of March 31, 2020, the remaining pre-funded warrants remain outstanding and are exercisable by the holders at any time.

The following table shows the common stock warrants outstanding as of March 31, 2020:

Warrant Issuance Date	Shares of CommonStock Underlying Warrants		Exercise Price/Share		Expiration Date
August 2014		28,713	$	23.51	2024
December 2014		144,772		14.00	2022
March 2016		45,307		2.76	2026
March 2018		18,123		7.73	2028
September 2019		2,234,925		0.01	N/A