Net Loss per Share

9 Months Ended

Sep. 30, 2020

Basic and diluted net loss per share attributable to common stockholders was calculated as follow:


	Three Months Ended September 30,				Nine Months Ended September 30,
(in thousands, except per share data)	2020		2019		2020		2019
Numerator:
Net loss	$	(17,449)	$	(17,714)	$	(43,731)	$	(41,970)
Accruing dividends on Series A convertible preferred stock	—		—		—		(592)
Net loss attributable to common stockholders	$	(17,449)	$	(17,714)	$	(43,731)	$	(42,562)
Denominator:
Weighted average common shares outstanding—basic and diluted	20,085		14,562		20,035		9,866
Net loss per share attributable to common stockholders— basic and diluted	$	(0.87)	$	(1.22)	$	(2.18)	$	(4.31)

The Company has included 107,371 shares of redeemable common stock, which were converted to common shares upon the Merger on March 13, 2019, in its computation of basic and diluted weighted average common shares outstanding for the nine months ended September 30, 2019 as this class of stock participated in losses similarly to other common stockholders. Basic and diluted weighted average common shares outstanding for the three and nine months ended September 30, 2020 also include the weighted average effect of 3,880,000 pre-funded warrants for the purchase of common shares for which the remaining unfunded exercise price is less than $0.01 per share.

The Company’s potentially dilutive securities include outstanding stock options, restricted stock units and warrants to purchase shares of common stock for the three and nine months ended September 30, 2020 and 2019. All potentially dilutive securities have been excluded from the computation of diluted net loss per share as the effect would be to reduce the net loss per share, and thus they are considered “anti-dilutive.” Therefore, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The Company excluded the following potential common shares, presented based on amounts outstanding at each period end, from the computation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:


	Three Months Ended September 30,		Nine Months Ended September 30,
	2020	2019	2020	2019
Options to purchase common stock	1,613,024	1,271,141	1,613,024	1,271,141
Unvested restricted stock units	611,994	116,689	611,994	116,689
Warrants to purchase common stock (excluding prefunded warrants, which are included in basic shares outstanding)	9,626,040	4,360,204	9,626,040	4,360,204
	11,851,058	5,748,034	11,851,058	5,748,034