Warrants

6 Months Ended

Jun. 30, 2020

As of June 30, 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	4,533,224
November 20, 2017	None	$	0.001	4,137,999
June 11, 2018	None	$	0.001	421,650
				9,092,873

During the three and six months ended June 30, 2020, 600,006 warrants for shares of the Company's common stock were exercised via cashless exercise, resulting in the issuance of 600,000 shares of common stock. No warrants were exercised during the three months ended June 30, 2019. During the six months ended June 30, 2019, 1,400,025 warrants for shares of the Company's common stock were exercised via cashless exercise, resulting in the issuance of 1,400,000 shares of common stock.

Shareholders' Equity

Sale of Common Stock

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 at $97.00 per share. After deducting underwriter discounts, commissions and offering expenses, the Company received net 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.

Share-based Compensation

Total share-based compensation expense by statement of operations and comprehensive loss classification is presented below (in thousands):



	Three Months Ended June 30,				Six Months Ended June 30,
	2020		2019		2020		2019
Research and development expense	$	11,457	$	6,611	$	23,305	$	11,768
General and administrative expense	9,330		5,978		19,049		11,952
	$	20,787	$	12,589	$	42,354	$	23,720

During the three and six months ended June 30, 2020, 323,789 and 820,310 shares were issued under our equity incentive plans, generating net proceeds of $8.7 million and $23.9 million, respectively. During the three and six months ended June 30, 2019, 97,489 and 332,887 shares were issued under our equity incentive plans, generating net proceeds of $1.6 million and $4.3 million, respectively.

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.