We are authorized to issue a total of 600.0 million shares of common stock as of December 31, 2019. Holders of our common stock are not entitled to receive dividends unless declared by our board of directors. As of December 31, 2019, we had 189.5 million shares of common stock outstanding and had reserved shares of common stock for future issuance as follows:



			December 31, 2019
			(in thousands)
Stock plans:
Options outstanding			1,154
RSUs ⁽¹⁾			8,733
Shares of common stock available for future grants:
2012 Equity Incentive Plan ⁽²⁾			29,641
2012 Employee Stock Purchase Plan ⁽²⁾			10,196
Total shares of common stock reserved for future issuance			49,724

During the years ended December 31, 2019 and 2018, we issued a total of 5.0 million shares and 5.9 million shares, respectively, from stock option exercises, vesting of RSUs, net of employee payroll taxes and purchases from ESPP. In addition, as described in Note 11, we issued approximately 4.3 million shares of our common stock upon the automatic exercise of the 2018 Warrants during the year end December 31, 2019, and received and retired 1.3 million shares of our common stock in conjunction with our exercise of the 2018 Note Hedge during the year end December 31, 2018.

Our board of directors has the authority, without further action by stockholders, to issue up to 10.0 million 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, 2019 and 2018, no shares of preferred stock were outstanding.