Net Loss per Share Attributable to Common Stock

12 Months Ended

Dec. 31, 2019

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, and convertible senior

notes, which are considered in the calculation of diluted net income per share whenever doing so would be dilutive.

As of December 31, 2019, we have one class of participating security, common stock, as all outstanding redeemable convertible preferred stock was converted to common stock on the date of our IPO, or August 2, 2017. Prior to August 2, 2017, we calculated basic and diluted net loss per share attributable to common stock in conformity with the two-class method required for companies with participating securities. Under the two-class method, net loss attributable to common stock was not allocated to the redeemable convertible preferred stock as the holders of redeemable convertible preferred stock did not have a contractual obligation to share in losses.

The following table sets forth the calculation of basic and diluted net loss per share attributable to common stock during the periods presented:



	Year Ended December 31,
	2019			2018			2017
Numerator:
Net loss	$	(80,805	)	$	(41,978	)	$	(15,002	)
Accretion of preferred stock	—			—			(175,915		)
Net loss attributable to common stock—basic and diluted	$	(80,805	)	$	(41,978	)	$	(190,917	)

Denominator:
Weighted average shares —basic and diluted	91,583,533			85,669,039			42,722,114
Net loss per share attributable to common stock—basic and diluted	$	(0.88	)	$	(0.49	)	$	(4.47	)

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. For the year ended December 31, 2017, shares of the redeemable convertible preferred stock were anti-dilutive. However, because the preferred stock converted into common stock on a one-for-one basis on August 2, 2017 upon the completion of our IPO, we included the preferred stock in the weighted average shares outstanding for the year ended December 31, 2017.



	Year Ended December 31,
	2019	2018	2017
Stock options outstanding	7,792,181	9,435,349	13,180,950
Restricted stock units outstanding	5,023,412	3,264,702	981,276
Employee stock purchase plan	—	—	—
Total	12,815,593	12,700,051	14,162,226

We are required to consider the impact of our convertible senior notes on our diluted net income per share based on the treasury stock method as we have the ability, and intent, to settle any conversions of the notes solely in cash. 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 effect from the notes.