Annual report pursuant to Section 13 and 15(d)

Stock-based Compensation

v3.3.1.900
Stock-based Compensation
12 Months Ended
Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]  
Stock-based Compensation
Stock-based Compensation
Equity Incentive Plans
In March 2010, our board of directors (the "Board") and stockholders approved the 2010 Equity Incentive Award Plan (the "2010 Plan"), which became effective upon the completion of our initial public offering (“IPO”) in April 2010. The number of shares of our common stock available for issuance under the 2010 Plan is equal to 1,100,000 shares plus any shares of common stock reserved for future grant or issuance under the Company’s 2002 Stock Plan (the “2002 Plan”) that remained unissued at the time of completion of the IPO. The 2010 Plan also provides for automatic annual increases in the number of shares reserved for future issuance. All grants will reduce the 2010 Plan reserve by one share for every share granted. As of December 31, 2015, total shares remaining available for issuance under the 2010 Plan were approximately 7.1 million shares.
The 2010 Plan provides for the grant of incentive stock options, non-statutory stock options, restricted stock award (“RSA”), restricted stock unit (“RSU”), performance-based awards, stock appreciation rights, and stock purchase rights to our employees, non-employee directors and consultants.
Incentive stock options may be granted with an exercise price of not less than the fair value of our common stock on the date of grant, and the nonstatutory stock options may be granted with an exercise price of not less than 85% of the fair value of our common stock on the date of grant, as determined by the Board. Stock options granted to a stockholder owning more than 10% of our voting stock must have an exercise price of not less than 110% of the fair value of the common stock on the date of grant. Stock options are granted with terms of up to ten years and generally vest over a period of four years.
RSAs, RSUs and Performance-Contingent RSUs (“PSUs”) may be granted for no consideration (other than par value of a share of common stock). The fair values of RSAs, RSUs and PSUs are based upon the closing price of our common stock on the date of grant. RSAs generally vest over one to three years. RSUs generally vest over three to four years. PSUs generally vest over two years and are conditional upon the attainment of one or more performance objectives over a specified period.
Stock-Based Compensation Expense:
Stock-based compensation expense is included in the consolidated statements of operations as follows (in thousands):
 
 
Years Ended December 31,
 
2015
 
2014
 
2013
Research and development
$
935

 
$
953

 
$
1,201

Selling, general and administrative
4,191

 
3,667

 
3,188

 
$
5,126

 
$
4,620

 
$
4,389


Grant Award Activities:
Stock Option Awards
We estimated the fair value of stock options using the Black-Scholes-Merton option-pricing model based on the date of grant. The following summarize the ranges of weighted-average assumptions used to estimate the fair value of employee stock options granted:
 
Years Ended December 31,
 
2015
 
2014
 
2013
Expected life (years)
6.1

 
6.0

 
6.0

Volatility
66.1
%
 
65.0
%
 
65.0
%
Risk-free interest rate
1.7
%
 
1.9
%
 
1.2
%
Expected dividend yield (1)
0.0
%
 
0.0
%
 
0.0
%
(1)
We do not currently pay dividends, and thus the dividend rate variable in the Black-Scholes-Merton option-pricing model is zero.
The following table summarizes stock option activity in 2015:
 
Number
of
Shares
 
Weighted
Average
Exercise Price Per Share
 
Weighted
Average
Remaining
Contractual Term
 
Aggregate Intrinsic
Value
 
(in thousands)
 
 
 
(in years)
 
(in thousands)
Balance at January 1, 2015
3,480

 
$
4.53

 
 
 
 
Granted
742

 
$
3.45

 
 
 
 
Exercised
(172
)
 
$
1.68

 
 
 
 
Forfeited/Expired
(132
)
 
$
3.58

 
 
 
 
Outstanding at December 31, 2015
3,918

 
$
4.49

 
6.41
 
$
4,206

 
 
 
 
 
 
 
 
Exercisable at December 31, 2015
2,499

 
$
5.42

 
5.20
 
$
2,252

Vested and expected to vest at December 31, 2015
3,771

 
$
4.54

 
6.31
 
$
4,036


The weighted average grant date fair value per share of stock options granted in 2015, 2014 and 2013 was $2.09, $1.20 and $1.34, respectively. The total intrinsic value of options exercised in 2015, 2014 and 2013 was $0.4 million, $57 thousand and $0.4 million, respectively.
As of December 31, 2015, there was $1.8 million unrecognized stock-based compensation cost related to nonvested options, which we expect to recognize over a weighted average period of 2.53 years.
Restricted Stock Awards
The following table summarizes the RSAs activity in 2015:
 
Number
of
Shares
 
Weighted Average
Grant Date
Fair Value
Per Share
 
(in thousands)
 
 
Nonvested balance at January 1, 2015
912

 
$
2.51

Granted
145

 
$
4.10

Vested
(577
)
 
$
2.27

Forfeited/Expired

 

Nonvested balance at December 31, 2015
480

 
$
3.29


The weighted average grant date fair value per share of RSAs granted in 2015, 2014 and 2013 was $4.10, $1.64 and $2.32, respectively. The total fair value of RSAs vested in fiscal 2015, 2014 and 2013 was $2.3 million, $0.7 million and $0.4 million respectively.
As of December 31, 2015, there was $0.7 million unrecognized stock-based compensation cost related to nonvested RSAs, which we expect to recognize over a weighted average period of 0.6 years.
Restricted Stock Units
The following table summarizes the RSUs activity in 2015:
 
Number
of
Shares
 
Weighted Average
Grant Date
Fair Value
Per Share
 
(in thousands)
 
 
Nonvested balance at January 1, 2015
1,052

 
$
2.22

Granted
339

 
$
3.65

Vested
(711
)
 
$
2.09

Forfeited/Expired
(135
)
 
$
2.73

Nonvested balance at December 31, 2015
545

 
$
3.15


The weighted average grant date fair value per share of RSUs granted in 2015, 2014 and 2013 was $3.65, $2.14 and $1.80, respectively. The total fair value of RSUs vested in fiscal 2015, 2014 and 2013 was $2.9 million, $1.9 million and $0.7 million respectively.
As of December 31, 2015, there was $0.9 million unrecognized stock-based compensation cost related to nonvested RSUs, which we expect to recognize over a weighted average period of 1.6 years.
Performance-Contingent RSUs
The following table summarizes the PSUs activity in 2015:
 
Number
of
Shares
 
Weighted Average
Grant Date
Fair Value
Per Share
 
(in thousands)
 
 
Nonvested balance at January 1, 2015
749

 
$
2.00

Granted
684

 
$
3.45

Vested
(195
)
 
$
2.00

Forfeited/Expired
(249
)
 
$
2.27

Nonvested balance at December 31, 2015
989

 
$
2.94


The weighted average grant date fair value per share of PSUs granted in 2015, 2014 and 2013 was $3.45, $2.00 and $2.32, respectively. The total fair value of PSUs vested in fiscal 2015 was $0.8 million. We had no PSUs vested in 2014 and 2013.
As of December 31, 2015, there was $0.7 million unrecognized stock-based compensation cost related to nonvested PSUs, which we expect to recognize over a weighted average period of 0.5 years.