Common stock and preferred stock

12 Months Ended

Dec. 31, 2019

The Company is authorized to issue 125.0 million shares of common stock. Holders of common stock are entitled to one vote per share. Holders of common stock are entitled to receive dividends, if and when declared by the Company’s board of directors, and to share ratably in the Company’s assets legally available for distribution to the Company’s shareholders in the event of liquidation. Holders of common stock have no preemptive, subscription, redemption or conversion rights. As of December 31, 2019, and 2018, the Company had 55.4 million and 54.7 million shares of common stock issued and outstanding, respectively.

In January 2018, the Company sold 0.3 million shares of common stock pursuant to the partial exercise of an overallotment option granted to the underwriters in connection with the December 2017 underwritten public offering at a price of $185.00 per share for aggregate net proceeds of $48.7 million. In July 2018, the Company sold 3.9 million shares of common stock (excluding any shares sold pursuant to an overallotment option granted to the underwriters in connection with the offering) through an underwritten public offering at a price of $162.50 per share for aggregate net proceeds of $600.6 million. In August 2018, the Company sold 0.4 million shares of common stock to Regeneron in connection with a collaboration arrangement at a price of $238.10 per share for aggregate net proceeds of $100.0 million, of which $45.5 million was attributed to a prepayment of joint research activities.

The Company is authorized to issue 5.0 million shares of preferred stock in one or more series and to fix the powers, designations, preferences and relative participating option or other rights thereof, including dividend rights, conversion rights, voting rights, redemption terms, liquidation preferences and the number of shares constituting any series, without any further vote or action by the Company’s shareholders. As of December 31, 2019 and 2018, the Company had no shares of preferred stock issued or outstanding.

Reserved for future issuance

The Company has reserved for future issuance the following number of shares of common stock (in thousands):


	As of December 31,
	2019	2018
Options to purchase common stock	5,483	4,643
Restricted stock units	1,127	931
2013 Stock Option and Incentive Plan	2,007	1,458
2013 Employee Stock Purchase Plan	147	172
	8,764	7,204