8. Redeemable Convertible Preferred Stock and Common Stock

As of September 30, 2018, the Company had 10,000,000 shares of preferred stock authorized and none issued and outstanding. As of December 31, 2017, the Company had 20,320,667 shares of preferred stock authorized, of which 15,527,951 shares were issued and outstanding and were designated as $0.0001 par value Series A Preferred Stock and 4,792,716 shares were issued and outstanding and were designated as $0.0001 par value Series B Preferred Stock.

Upon completion of the Company’s initial public offering in January 2018, all the outstanding preferred stock of the Company automatically converted into 15,870,559 shares of the Company’s common stock. As of September 30, 2018, no shares of preferred stock were outstanding.

Reserve for future issuance

The Company has reserved the following number of shares of common stock for future issuance upon the conversion of preferred stock, exercise of options or grant of equity awards:

	September 30, 2018		December 31, 2017
Redeemable convertible preferred stock, on an as-converted basis		—		15,870,559
Options issued and outstanding		1,066,678		195,668
Unvested restricted stock units		24,960		—
Options available for future grants		1,413,610		1,670,341
Shares available for issuance under the 2018 ESPP		275,030		—
Total		2,780,278		17,736,568