Net Income (Loss) Per Common Share

12 Months Ended

Dec. 31, 2020

Net Income (Loss) Per Common ShareBasic and diluted net loss per common share is determined by dividing net loss by the weighted average common shares and pre-funded warrants outstanding during the period. Basic and diluted shares outstanding includes the weighted average effect of the Company's outstanding pre-funded warrants as the exercise of such pre-funded warrants requires nominal consideration to be given for the delivery of the corresponding shares of common stock. As of December 31, 2020 and 2019, the Company had 3,164,280 and 3,750,000 pre-funded warrants outstanding, respectively, which if exercised, would increase the number of shares of common stock issued and outstanding. For the periods when there is a net loss, shares underlying stock options and RSUs have been excluded from the calculation of diluted net loss per common share because the effect of including such shares would be anti-dilutive. Therefore, the weighted average common shares used to calculate both basic and diluted net loss per common share would be the same.

The following table sets forth the computation of basic and diluted net income (loss) per common share for the periods indicated:


	Years ended December 31,
	2020		2019		2018
Basic and diluted net income (loss) per common share calculation:
Net income (loss)	$	(84,547)	$	(58,859)	$	63,087
Weighted average common shares outstanding - basic	74,185		42,224		37,061
Plus: net effect of dilutive stock options and unvested restricted stock units	—		—		27
Weighted average common shares outstanding - dilutive	74,185		42,224		37,088
Net income (loss) per common share - basic	$	(1.14)	$	(1.39)	$	1.70
Net income (loss) per common share - diluted	$	(1.14)	$	(1.39)	$	1.70

The following potentially dilutive securities have been excluded from the computations of diluted weighted average common shares outstanding for the periods presented, as the effect of including such shares would be anti-dilutive:


	Years ended December 31,
	2020	2019	2018
Stock options outstanding	8,928	6,780	5,873
Restricted stock units	1,958	1,481	601
Total	10,886	8,261	6,474