Stock-Based Compensation

Stock-based compensation expense was attributable to:



	Year Ended
	October 3, 2015		September 27, 2014		September 28, 2013
	(In thousands)
Stock options	$	9,894	$	9,820	$	10,506
Restricted stock units	10,759		8,969		7,018
Total	$	20,653	$	18,789	$	17,524

Stock-based compensation expense was as follows:



	Year Ended
	October 3, 2015		September 27, 2014		September 28, 2013
	(In thousands)
Cost of sales	$	6,611	$	5,849	$	5,464
Selling, general & administrative	13,859		12,861		11,942
Research & development	183		79		118
Total	$	20,653	$	18,789	$	17,524

Stock Options

The Company's stock option plans provide employees the right to purchase common stock at the fair market value of such shares on the grant date. The Company recognizes compensation expense for such awards over the vesting period, which is generally four to five years. The contractual term of all options is ten years, at which time such options would expire. The Company recognizes compensation expense ratably over the service period.

Assumptions used to estimate the fair value of stock options granted were as follows:



	Year Ended
	October 3, 2015		September 27, 2014		September 28, 2013
Volatility	52.9	%	67.6	%	86.0	%
Risk-free interest rate	1.6	%	1.5	%	0.7	%
Dividend yield	—		—		—
Expected life of options	5.0		5.0		5.0

Stock option activity was as follows:



	Number of Shares		Weighted-Average Exercise Price ($)	Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value of In-The-Money Options ($)
	(In thousands)				(In thousands)
Outstanding as of September 29, 2012	11,275		13.15	6.54	18,548
Granted	975		8.83
Exercised/Cancelled/Forfeited/Expired	(2,688	)	13.36
Outstanding as of September 28, 2013	9,562		12.65	5.99	62,825
Granted	648		15.89
Exercised/Cancelled/Forfeited/Expired	(2,029	)	12.67
Outstanding as of September 27, 2014	8,181		12.90	5.30	93,767
Granted	567		24.48
Exercised/Cancelled/Forfeited/Expired	(1,715	)	16.13
Outstanding as of October 3, 2015	7,033		13.05	4.94	53,938
Vested and expected to vest as of October 3, 2015	6,942		12.97	4.89	53,609
Exercisable as of October 3, 2015	5,917		12.25	4.33	48,655

The weighted-average grant date fair value of stock options granted during 2015, 2014 and 2013 was $12.46, $9.14, and $5.91, respectively. The aggregate intrinsic value in the preceding table represents the total pre-tax intrinsic value of in-the-money options that would have been received by the option holders had all option holders exercised their options at the Company's closing stock price on the date indicated. The total intrinsic value of stock options exercised was $16.2 million for 2015, $18.3 million for 2014 and $12.1 million for 2013.

As of October 3, 2015, unrecognized compensation expense of $7.1 million is expected to be recognized over a weighted average period of 1.9 years.

The following table summarizes information regarding stock options outstanding at October 3, 2015:



Options Outstanding				Options Vested and Exercisable
Range of Weighted Exercise Prices	Number Outstanding	Weighted Average Remaining Contractual Life (Years)	Weighted Average Exercise Price ($)	Number Exercisable	Weighted Average Exercise Price ($)
	(In thousands)			(In thousands)
$1.50-$6.89	794	3.59	3.55	793	3.55
$6.90-$8.69	774	6.45	8.47	513	8.48
$8.70-$8.81	1,350	4.83	8.76	1,323	8.76
$8.82-$11.57	920	5.45	10.56	837	10.54
$11.58-$15.76	959	5.69	13.86	732	13.40
$15.77-$21.11	496	5.88	16.51	468	16.44
$21.12-$28.20	1,740	4.01	22.62	1,251	21.89
$1.50-$28.20	7,033	4.94	13.05	5,917	12.25

Restricted Stock Units

The Company issues restricted stock units to executive officers, directors and certain management employees. These units vest over periods ranging from one to four years or based upon achievement of specified performance criteria and are automatically exchanged for shares of common stock at the vesting date. Compensation expense associated with these units is recognized ratably over the vesting period.

Activity with respect to the Company's restricted stock units was as follows:



	Number of Shares		Weighted Grant-Date Fair Value Per Share ($)	Weighted-Average Remaining Contractual Term (Years)	Aggregate Intrinsic Value ($)
	(In thousands)				(In thousands)
Outstanding as of September 29, 2012	2,230		9.51	1.08	21,272
Granted	1,167		9.42
Vested/Forfeited/Cancelled	(1,629	)	7.93
Outstanding as of September 28, 2013	1,768		10.90	2.02	31,052
Granted	1,204		17.16
Vested/Forfeited/Cancelled	(631	)	13.99
Outstanding as of September 27, 2014	2,341		13.29	2.01	56,064
Granted	966		23.42
Vested/Forfeited/Cancelled	(328	)	13.79
Outstanding as of October 3, 2015	2,979		16.52	1.52	59,843
Expected to vest as of October 3, 2015	2,739		16.28	1.44	39,386

The weighted-average grant date fair value of restricted stock units granted was $23.42, $17.16 and $9.42 in 2015, 2014 and 2013, respectively. The total fair value of restricted stock units vested was $6.7 million for 2015, $9.2 million for 2014 and $8.3 million for 2013. As of October 3, 2015, unrecognized compensation expense of $20.0 million is expected to be recognized over a weighted average period of 1.5 years. Additionally, as of October 3, 2015, unrecognized compensation expense related to performance-based restricted stock units for which achievement of vesting criteria is not considered probable was $13.6 million.