4. Net Income (Loss) Per Share

The following table sets forth the computation of basic and diluted net loss per share (in thousands, except per share data).

	Three Months Ended					Nine Months Ended
	September 30,					September 30,
	2017		2016			2017		2016
Net income (loss)	$	1,998	$	(333	)	$	1,825	$	(25,735	)
Weighted average common basic shares		41,200		41,096			41,174		41,074
Effect of dilutive securities		33		—			63		—
Weighted average common dilutive shares		41,233		41,096			41,237		41,074
Basic and diluted net income (loss) per share	$	0.05	$	(0.01	)	$	0.04	$	(0.63	)

On May 9, 2017, the Compensation Committee of the Board of Directors of the Company awarded 500 thousand restricted stock units to an executive officer. Such restricted stock units will vest, and an equal number of shares of common stock will be deliverable upon the third anniversary of the date of grant. Compensation expense related to the units of $590 thousand was calculated based upon the closing market price of the common stock on the date of grant ($1.18) and is recorded on a straight-line basis over the vesting period.

For the three and nine months ended September 30, 2017, the computation of diluted net income per share included 576 restricted stock units having dilutive effects of 33 and 63 thousand shares, respectively. Options to purchase 120 thousand shares and 93 thousand restricted stock units were not included in the computation of diluted net income per share for these periods, since the exercise price of the stock options was in excess of the average stock price for this period and the inclusion of the restricted stock units would have been anti-dilutive.

For the three months ended September 30, 2016, the computation of diluted net loss per share did not include 270 thousand restricted stock units, a dilutive effect of 5 thousand shares, since their inclusion would have been anti-dilutive. Options to purchase 1,045 thousand shares were not included in the computation of diluted net loss per share for the three months ended September 30, 2016, since their exercise price was in excess of the average stock prices for these periods.

For the nine months ended September 30, 2016, the computation of diluted net loss per share did not include options to purchase 825 thousand shares and 270 thousand restricted stock units, a dilutive effect of 176 thousand shares and 23 thousand shares, respectively, since their inclusion would have been anti-dilutive. Options to purchase 220 thousand shares were not included in the computation of diluted net loss per share for the nine months ended September 30, 2016, since their exercise price was in excess of the average stock prices for these periods.