Basic net loss per common share is computed by dividing the net loss by the weighted-average number of common shares outstanding during the period. Diluted net loss per common share is computed using net loss and the weighted-average number of common shares outstanding plus potentially dilutive common shares outstanding during the period. Potentially dilutive common shares include the assumed exercise of outstanding in-the-money stock options and common stock warrants, assumed release of outstanding RSUs, and assumed issuance of common stock under the ESPP using the treasury stock method.

The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders (in thousands, except share and per share amounts):

	Year Ended December 31,
	2021			2020			2019
Net loss	$	(65,226	)	$	(41,280	)	$	(25,084	)
Weighted-average common shares outstanding—basic and diluted		43,886,730			34,374,903			18,011,470
Net loss per common share—basic and diluted	$	(1.49	)	$	(1.20	)	$	(1.39	)

The Company incurred net losses in the periods presented, and as a result, potential common shares from stock options, common stock warrants, RSUs, and the assumed release of outstanding shares under the ESPP were not included in the diluted shares used to calculate net loss per share, as their inclusion would have been anti-dilutive. The following table sets forth the potentially dilutive shares excluded from the computation of diluted net loss per common share because their effect was anti-dilutive:

	Year Ended December 31,
	2021		2020		2019
Common stock warrants		—		—		127,598
Options to purchase common stock		5,423,419		5,369,306		4,731,435
Unvested restricted stock units		1,679,696		619,218		120,000
ESPP		87,367		58,802		75,405
Total		7,190,482		6,047,326		5,054,438