Net Loss per Share Attributable to Common Stock

12 Months Ended

Dec. 31, 2020

Net Loss per Share Attributable to Common Stock

Net loss per share attributable to common stock is computed by dividing the net loss attributable to common stock by the weighted-average number of common shares outstanding. We have outstanding stock options, restricted stock units, options to purchase shares under our ESPP, convertible preferred stock, and convertible senior notes, which are considered in the calculation of diluted net income per share whenever doing so would be dilutive.

We calculate basic and diluted net loss per share attributable to common stock in conformity with the two-class method required for companies with participating securities. We consider our convertible preferred stock to be a participating security. Under the two-class method, net loss attributable to common stock is not allocated to the preferred stock as its holders do not have a contractual obligation to share in losses, as discussed in Note 11.

The calculation of basic and diluted net loss per share attributable to common stock was as follows:


	Year Ended December 31,
	2020		2019		2018
Numerator:
Net loss	$	(18,527)	$	(80,805)	$	(41,978)
Dividends on convertible preferred stock	(4,454)		—		—
Net loss attributable to common stock—basic and diluted	$	(22,981)	$	(80,805)	$	(41,978)

Denominator:
Weighted average shares—basic and diluted(1)	98,574,529		91,583,533		85,669,039
Net loss per share attributable to common stock—basic and diluted	$	(0.23)	$	(0.88)	$	(0.49)

(1) Basic and diluted weighted average shares outstanding include (i) common stock earned but not yet issued related to share-based dividends on our convertible preferred stock, and (ii) restricted stock units whose settlement into common stock were deferred at the option of certain non-employee directors.

The following outstanding shares of common stock equivalents were excluded from the computation of the diluted net loss per share attributable to common stock for the periods presented because their effect would have been anti-dilutive.


	Year Ended December 31,
	2020	2019	2018
2023 notes as if converted(1)	838,821	—	—
2025 notes as if converted	9,119,960	—	—
Convertible preferred stock as if converted	2,040,000	—	—
Stock options outstanding	5,733,738	7,792,181	9,435,349
Restricted stock units outstanding(2)	4,443,315	5,023,412	3,264,702
Total	22,175,834	12,815,593	12,700,051

(1) Includes $1,849 principal amount of 2023 notes with respect to which we received conversion requests by December 31, 2020. See Note 1.

(2) Excludes 16,428 restricted stock units whose settlement into common stock were deferred at the option of certain non-employee directors as of December 31, 2020.

We intend to settle any conversion of our 2023 and 2025 notes in cash, shares, or a combination thereof. The dilutive impact of the notes on our net loss per share is considered using the if-converted method for the year ended December 31, 2020. For periods ending prior to December 31, 2020, we considered the impact of the notes on our diluted net income (loss) per share based on applying the treasury stock method as we had the ability, and intent, to settle any conversions of the notes solely in cash at that time. The treasury stock method requires that the dilutive effect of common stock issuable upon conversion of the notes be computed in the periods in which we report net income. For the year ended December 31, 2019 there was no dilutive impact from the notes.