7. Common Stock

As of December 31, 2019, the amended and restated certificate of incorporation authorizes the Company to issue 290 million shares of common stock and 10 million shares of preferred stock.

Each share of common stock is entitled to one vote. Common stockholders are entitled to dividends if and when declared by the board of directors. As of December 31, 2019, no dividends on common stock had been declared.

The Company has reserved shares of common stock, for issuance as follows:


	December 31,
	2019	2018	2017
Exchange warrants	1,458,000	—	—
Shares available for future option grants	1,704,183	2,486,637	2,576,535
Outstanding options	5,643,410	3,778,259	3,013,394
Unvested restricted common stock (founders and early exercise of stock options)	—	43,076	319,203
Shares reserved for employee stock purchase plan	400,000	400,000	400,000
Total	9,205,593	6,707,972	6,309,132