Net Loss Per Share

9 Months Ended

Sep. 30, 2015

3. Net Loss Per Share

We compute net loss per common share by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding during the period. Potentially dilutive securities consisting of stock issuable under options and our 2013 Employee Stock Purchase Plan (ESPP) are not included in the diluted net loss per common share calculation where the inclusion of such shares would have had an antidilutive effect.

Basic and diluted (loss) per common share is computed as follows (in thousands except share and per share data)


	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2015		2014		2015		2014
	(in thousands, except
	per share data)
Basic numerator:
Net loss attributable to common stockholders	$	(10,037)	$	(6,278)	$	(25,349)	$	(15,073)
Denominator:
Weighted-average common shares outstanding used in computing basic and diluted net loss		40,473,520		31,395,626		38,514,179		31,376,502
Basic net loss per common share	$	(0.25)	$	(0.20)	$	(0.66)	$	(0.48)

The following shares of outstanding potentially dilutive securities have been excluded from the calculation of diluted net loss per common share as the effect of including such securities would have been antidilutive.


	Three Months Ended		Nine Months Ended
	September 30,		September 30,
	2015	2014	2015	2014
	(in thousands)		(in thousands)
Employee stock purchase plan shares	31	34	31	34
Options to purchase common stock	3,378	1,361	3,378	1,361
	3,409	1,395	3,409	1,395

In March 2015, the Company issued 8,625,000 shares of common stock in a follow-on stock offering. The issuance of these shares resulted in a significant increase in the Company’s weighted average shares outstanding for the three months and nine months ended September 30, 2015 when compared to the comparable prior year period and is expected to continue to impact the year-over-year comparability of the Company’s income (loss) per share calculations for the remainder of 2015.