12.Net Loss per Share

Diluted loss per share is the same as basic loss per share for all periods presented because the effects of potentially dilutive items were anti-dilutive given the Company’s net loss. The following securities have been excluded from the calculation of weighted average common shares outstanding because the effect is anti-dilutive:

	Three and Nine Months Ended September 30,
	2013	2014
Redeemable convertible preferred stock:
Series A	10,033,976	—
Series B	5,057,901	—
Series C	4,429,601	—
Series D	3,979,730	—
Warrants to purchase Series D redeemable convertible preferred stock	12,797	—
Stock options	5,483,948	6,282,657
Restricted stock units	—	1,013,239

Basic and diluted net loss per share attributable to common stockholders is calculated as follows:

	Three Months Ended September 30,						Nine Months Ended September 30,
	2013			2014			2013			2014
Numerator (in thousands):
Net loss attributable to common stockholders	$	(10,220	)	$	(7,337	)	$	(23,035	)	$	(25,071	)
Denominator:
Weighted-average common shares outstanding, basic and diluted	7,415,777			40,269,937			7,401,842			29,209,970
Net loss per share attributable to common stockholders, basic and diluted	$	(1.38	)	$	(0.18	)	$	(3.11	)	$	(0.86	)