NET LOSS PER SHARE

Basic net loss per share is computed by dividing net loss by the weighted average number of common shares outstanding (excluding shares of restricted stock). Shares issued during the period and shares reacquired during the period are weighted for the portion of the period they were outstanding. Diluted net loss per share is computed in a manner consistent with that of basic net loss per share, while giving effect to all potentially dilutive common shares outstanding during the period, which include the assumed exercise of stock options and the assumed vesting of restricted stock using the treasury stock method, and the assumed conversion of shares under the Notes using the “if-converted” method.

Options to purchase common stock, the vesting of RSAs, RSUs and PSUs, and shares issuable upon conversion of the Notes are considered to be potentially dilutive common shares but have been excluded from the calculation of diluted net loss per share as their effect is anti-dilutive for the three and six months ended June 30, 2017 and 2016 as a result of the net losses incurred in those periods. Therefore, diluted net loss per share was the same as basic net loss per share for the three and six months ended June 30, 2017 and 2016. Stock options, RSUs, restricted stock awards, PSUs, and shares issuable upon the conversion of the Notes outstanding at June 30, 2017 and 2016, which are excluded from the computation of diluted net loss per share for the three and six months ended June 30, 2017 and 2016, are shown in the table below:



	Six Months Ended June 30,
	2017	2016
Options to purchase common stock	2,844,797	3,317,312
Non-vested RSAs and RSUs	534,373	389,636
Non-vested PSUs	487,847	745,942
Shares issuable upon conversion of the Notes	7,337,459	7,337,459
Potentially dilutive common shares	11,204,476	11,790,349

A summary of the net loss per share calculation is shown below for the periods indicated (in thousands, except share and per share amounts):



	Three Months Ended June 30,						Six Months Ended June 30,
	2017			2016			2017			2016
Net loss	$	(24,604	)	$	(14,906	)	$	(43,128	)	$	(32,197	)
Common shares outstanding:
Historical common shares outstanding at beginning of period (1)	43,716,110			42,772,670			43,254,655			42,632,771
Weighted average common shares issued	18,308			31,783			358,818			118,117
Weighted average common shares outstanding — basic and diluted	43,734,418			42,804,453			43,613,473			42,750,888
Net loss per share — basic and diluted	$	(0.56	)	$	(0.35	)	$	(0.99	)	$	(0.75	)


(1)	RSAs that are issued but contingent on a one year vesting period have been excluded from this balance.