EARNINGS PER SHARE

12 Months Ended

Dec. 31, 2021

Basic net income (loss) per share is computed by dividing the net income (loss) attributable to common stockholders for the applicable period by the weighted average number of common shares outstanding during the period. Potentially dilutive shares, consisting of outstanding stock options, RSUs, ESPP awards, warrants, and the Company’s Notes, are included in calculation of diluted net income (loss) per share when their effect is dilutive.

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


	Year ended December 31,
(in thousands, except per share amounts)	2021		2020		2019
Numerator:
Net income (loss)	$	13,254	$	(29,271)	$	(5,924)
Denominator:
Weighted average number of shares outstanding:
Basic	101,484		96,971		89,575
2020 Notes	2,175		—		—
2024 Notes	653		—		—
Stock options	292		—		—
Restricted stock units	1,525		—		—
Stock purchase rights under ESPP	42		—		—
Diluted	106,171		96,971		89,575
Net income (loss) per share:
Basic	$	0.13	$	(0.30)	$	(0.07)
Diluted	$	0.12	$	(0.30)	$	(0.07)

The following table presents the potentially dilutive shares that were excluded from the computation of diluted net income (loss) per share, because their effect was anti-dilutive:


	Year ended December 31,
(in thousands)	2021	2020	2019
2020 Notes	—	312	1,322
2022 Notes	—	192	n/a
Stock options	8	1,603	2,568
Restricted stock units	27	3,041	2,955
Stock purchase rights under the ESPP	390	531	478
Warrants (1)	—	—	4,321
Total	425	5,679	11,644

(1) Refer to Note 15, “Warrants,” for additional information.

The Company applies the treasury stock method to determine the potential dilutive effect of its convertible debt on earnings per share. The 2020 Notes, 2022 Notes, and 2024 Notes are excluded from the calculation of diluted earnings per share under the treasury stock method for the periods when their respective conversion prices exceeded the average market price for the Company's common stock. Under the if-converted method, the 2022 Notes and the 2024 Notes have potential dilutive effect of 6.6 million shares and 13.3 million shares, respectively.