Stockholders' Equity

Common Stock

We are authorized to issue a total of 600,000,000 shares of common stock as of December 31, 2017. Holders of our common stock are not entitled to receive dividends unless declared by our board of directors. As of December 31, 2017, we had 174,275,864 shares of common stock outstanding and had reserved shares of common stock for future issuance as follows:



			December 31, 2017
Stock plans:
Options outstanding			3,369,732
RSUs ⁽¹⁾			11,403,341
Stock awards available for future grants:
2012 Equity Incentive Plan ⁽²⁾			25,813,848
2012 Employee Stock Purchase Plan ⁽²⁾			9,581,944
Total reserved shares of common stock for future issuance			50,168,865


(1)	Represents the number of shares issuable upon settlement of outstanding RSUs and performance RSUs, assuming 100% of the target number of shares for performance RSUs, as discussed under the section entitled “RSUs” in Note 12.


(2)	Refer to Note 12 for a description of these plans.

During the years ended December 31, 2017 and 2016, we issued a total of 7,385,897 shares and 6,645,009 shares, respectively, from stock option exercises, vesting of RSUs, net of employee payroll taxes and purchases from ESPP. In May 2017, we repurchased and retired 540,806 shares of our common stock for approximately $55.0 million, or $101.70 per share, from certain purchasers of the 2022 Notes in connection with the 2022 Notes offering. We had no similar repurchases or retirements of common stock during the year ended December 31, 2016.

Preferred Stock

Our board of directors has the authority, without further action by stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series. Our board of directors may designate the rights, preferences, privileges and restrictions of the preferred stock, including dividend rights, conversion rights, voting rights, terms of redemption, liquidation preference and number of shares constituting any series or the designation of any series. The issuance of preferred stock could have the effect of restricting dividends on our common stock, diluting the voting power of our common stock, impairing the liquidation rights of our common stock, or delaying or preventing a change in control. At December 31, 2017 and 2016, no shares of preferred stock were outstanding.