7. Stockholders’ Equity

Stock-based Compensation

On December 11, 2017, our stockholders approved our Amended and Restated 2012 Incentive Award Plan (the “2012 Plan”), which, among other things, increased the maximum number of shares of common stock which may be issued under such plan by 1.6 million shares. As of March 31, 2018, we maintained the following share based employee compensation plans: the 2012 Plan and the Amended and Restated 2006 Equity Participation Plan (“2006 Plan”). No further grants may be made under the 2006 Plan. In addition, pursuant to the acquisition of AS&E, we assumed two share based employee compensation plans: the AS&E 2005 Equity and Incentive Plan (“2005 AS&E Plan”) and the AS&E 2014 Equity and Incentive Plan (“2014 AS&E Plan”). No new RSU grants will be made under the 2005 AS&E Plan or the 2014 AS&E Plan. The 2012 Plan, the 2006 Plan, the 2005 AS&E Plan and the 2014 AS&E Plan are collectively referred to as the “OSI Plans”.

We recorded stock-based compensation expense in the condensed consolidated statements of operations as follows (in thousands):

	Three Months Ended March 31,						Nine Months Ended March 31,
	2017			2018			2017			2018
Cost of goods sold	$	417		$	251		$	1,116		$	739
Selling, general and administrative	5,627			5,614			15,909			16,574
Research and development	159			149			335			441
Restructuring	—			—			2,902			—

Stock-based compensation expense before taxes	$	6,203		$	6,014		$	20,262		$	17,754
Less: related income tax benefit	(2,378		)	(1,864		)	(7,828		)	(5,492		)

Stock-based compensation expense, net of estimated taxes	$	3,825		$	4,150		$	12,434		$	12,262

As of March 31, 2018, total unrecognized compensation cost related to share based compensation grants under the OSI Plans were estimated at $0.7 million for stock options and $19.9 million for RSUs. We expect to recognize these costs over a weighted average period of 2.0 years with respect to the stock options and 1.9 years for grants of RSUs.

The following summarizes stock option activity during the nine months ended March 31, 2018:

	Number of Options		Weighted Average Exercise Price		Weighted- Average Remaining Contractual Term	Aggregate Intrinsic Value (in thousands)
Outstanding at June 30, 2017	780,671		$	30.00
Granted	25,379		$	85.83
Exercised	(113,255	)	$	22.73
Expired or forfeited	(5,730	)	$	73.38

Outstanding at March 31, 2018	687,065		$	32.89	3.2 years	$	23,193

Exercisable at March 31, 2018	642,629		$	29.63	2.8 years	$	23,190

The following summarizes RSU activity during the nine months ended March 31, 2018:

	Shares		Weighted- Average Fair Value
Nonvested at June 30, 2017	611,687		$	65.85
Granted	349,538		74.11
Vested	(401,773	)	65.27
Forfeited	(13,919	)	70.11

Nonvested at March 31, 2018	545,533		$	71.46

As of March 31, 2018, there were approximately 2.3 million shares available for grant under the 2012 Plan. Under the terms of the 2012 Plan, RSUs and restricted stock granted from the pool of shares available for grant reduce the pool by 1.87 shares for each award granted. RSUs and restricted stock forfeited and returned to the pool of shares available for grant increase the pool by 1.87 shares for each award forfeited.

We granted 155,488 and 117,346 performance-based RSUs during the nine months ended March 31, 2017 and 2018, respectively. These performance-based RSUs are contingent on the achievement of certain performance metrics. The payout can range from zero to 250% of the original number of shares or units awarded.

Share Repurchase Program

In April 2016, the Board of Directors authorized a share repurchase program of up to one million shares, which was completed during the three months ended March 31, 2018. In March 2018, the Board of Directors authorized a new share repurchase program up to one million shares. This program does not expire unless our Board of Directors acts to terminate the program. The timing and actual number of shares purchased depend on a variety of factors, including stock price, general business and market conditions and other investment opportunities and may be purchased through the open market. Upon repurchase, the shares are restored to the status of authorized but unissued, and we record them as a reduction in the number of shares of common stock issued and outstanding in our consolidated financial statements.

During the three and nine months ended March 31, 2018, we repurchased 972,481 shares of our common stock.