9. Stockholders’ Equity (Tables)

6 Months Ended

Jun. 30, 2015

Stockholders Equity Tables

Stock option assumptions

The weighted average fair value of stock options granted during the periods and the assumptions used to estimate those values using the Black-Scholes option pricing mode were as follows:

		Three Months Ended						Six Months Ended
		June 30,						June 30,
		2015			2014			2015			2014
Weighted average expected
stock price volatility		73.2	%		75.5	%		73.3	%		74.5	%
Estimated dividend yield		-	%		-	%		-	%		-	%
Risk-free interest rate		1.6	%		2.0	%		1.6	%		1.9	%
Expected life of option (in years)		6.3			6.3			6.3			6.2
Weighted average grant date
fair value per option	$	5.16		$	4.59		$	5.59		$	2.74

Stock option activity

The following table shows the option activity, described above, during the six months ended June 30, 2015 (share and intrinsic values in thousands):

				Weighted Average
			Average	Remaining		Aggregate
			Exercise	Contractual Life		Intrinsic
	Shares		Price	years		Value
Options Outstanding at December 31, 2014	4,551	$	5.35
Granted	1,088		8.49
Exercised	(39)		3.92		$	211
Cancelled	(208)		8.68
Expired	-		-
Options outstanding at June 30, 2015	5,392	$	5.86	8.9	$	7,227
Options vested and expected to
vest as of June 30, 2015	4,578		5.80	8.8	$	6,293
Options vested and exercisable as of June 30, 2015	1,044	$	4.85	8.0	$	1,910

Restricted stock activity

The following table shows the Company's non-vested restricted stock activity during the six months ended June 30, 2015 (share and intrinsic values in thousands):

			Weighted Average		Aggregate
			Grant Date Fair		Intrinsic
	Shares		Value		Value
Non-vested restricted stock outstanding at December 31, 2014	140	$	4.52
Granted	-		-
Vested	(56)		6.09	$	539
Forfeited	(19)		3.16
Non-vested restricted stock outstanding at June 30, 2015	65	$	3.56