Shareholders' Equity

12 Months Ended

Dec. 31, 2020

Common Stock

The following shares were reserved for future issuance:


			December 31, 2020
Common stock options outstanding			4,429,489
Restricted stock units outstanding			465,260
Warrants to purchase common stock			8,229,632
Employee Stock Purchase Plan			128,436
Shares available for grant			1,708,448
Total			14,961,265

Sale of Common Stock

In October 2020, the Company sold 4,585,706 shares of its common stock at a public offering price of $202.00 per share. After deducting underwriter discounts, commissions and estimated offering expenses, the Company received net proceeds from the transaction of approximately $879.6 million.

In January 2020, the Company sold 3,538,462 shares of its common stock at a public offering price of $97.50 per share. After deducting underwriter discounts, commissions and offering expenses, the Company received net proceeds from the transaction of $324.0 million.

In June 2019, the Company sold 2,415,000 shares of its common stock at a public offering price of $97.00 per share. After deducting underwriter discounts, commissions and offering expenses, the Company received net cash proceeds from the transaction of $219.9 million.

In January 2019, the Company sold 1,854,838 shares of its common stock at a public offering price of $62.00 per share. After deducting underwriter discounts, commissions and offering expenses, the Company received net cash proceeds from the transaction of $107.9 million.

At-the-Market Facility

On July 2, 2020, the Company entered into a sales agreement pursuant to which the Company may, from time to time, sell shares of the Company's common stock, par value $0.001 per share, having an aggregate offering price of up to $200.0 million. As of December 31, 2020, the Company has not offered or sold any shares of common stock pursuant to this sales agreement.

Disgorgement Proceeds

In January 2019, the Company received a payment of $1.1 million representing a disgorgement of short-swing profits from the sale of common stock by a beneficial owner pursuant to Section 16(b) of the Securities Exchange Act of 1934, as amended. In January 2020, the Company received an immaterial disgorgement of short-swing profits. The Company recognized these proceeds as a capital contribution from shareholders and reflected a corresponding increase to additional paid-in capital.

Warrants

As of December 31, 2020, the following warrants for common stock were issued and outstanding:


Issue date	Expiration date	Exercise price		Number of warrants outstanding
January 11, 2017	None	$	0.001	3,733,218
November 20, 2017	None	$	0.001	4,137,999
June 11, 2018	None	$	0.001	358,415
				8,229,632

During the year ended December 31, 2020, warrants for 1,400,012 shares of the Company's common stock were exercised via cashless exercises, resulting in the issuance of 1,400,000 shares of common stock, and warrants for 63,235 shares of the common stock were exercised for cash, generating immaterial net proceeds.

During the year ended December 31, 2019, warrants for 2,125,033 shares of the Company's common stock were exercised via cashless exercise, resulting in the issuance of 2,125,000 shares of common stock.

During the year ended December 31, 2018, no warrants were exercised.