Common stock (Tables)

12 Months Ended

Dec. 31, 2020

Common stock.

Schedule of shares reserved for future issuance

Shares Reserved For Future Issuance

	As of December 31,
	2020	2019
Shares reserved for vesting of restricted stock awards under the Founder Agreements	156,863	176,471
Shares reserved for exercise of outstanding stock options	5,485,078	5,317,326
Shares reserved for vesting of outstanding restricted stock units	638,471	455,404
Shares reserved for issuances under the 2015 Stock Option Plan	2,827,185	1,875,078
Shares reserved for issuances under the 2015 Employee Stock Purchase Plan	1,484,923	1,218,876
	10,592,520	9,043,155