Stockholders' Equity

Share-based Compensation Plans

We maintain two share-based employee compensation plans: the 2012 Equity Incentive Plan (2012 Plan) and the 2005 Stock Plan (collectively, Stock Plans). Our 2012 Plan serves as the successor to our 2005 Stock Plan and provides for the issuance of incentive and nonstatutory stock options, restricted stock awards, stock appreciation rights, RSUs, performance shares, and stock bonuses to qualified employees, directors and consultants. Outstanding awards under the 2005 Stock Plan continue to be subject to the terms and conditions of the 2005 Stock Plan.

We initially reserved 25 million shares of our Class A common stock for issuance under our 2012 Plan. The number of shares reserved for issuance under our 2012 Plan increases automatically on the first day of January of each of 2013 through 2022 by a number of shares of Class A common stock equal to the lesser of (i) 2.5% of the total outstanding shares of our Class A common stock as of the immediately preceding December 31st or (ii) a number of shares determined by our board of directors. Our board of directors elected not to increase the number of shares reserved for issuance in 2016. In addition, shares available for grant under the 2005 Stock Plan, which were reserved but not issued, forfeited, or repurchased at their original issue price, or subject to outstanding awards under the 2005 Stock Plan as of the effective date of our IPO, were added to the reserves of the 2012 Plan. The maximum term for stock options granted under the 2012 Plan may not exceed ten years from the date of grant. Our 2012 Plan will terminate ten years from the date of approval unless it is terminated earlier by our board of directors or a committee thereof.

The following table summarizes the activities of stock option awards under the Stock Plans for the three months ended March 31, 2016:



	Shares Subject to Options Outstanding
	Number of Shares		Weighted Average Exercise Price		Weighted Average Remaining Contractual Term	Aggregate Intrinsic Value⁽¹⁾
	(in thousands)				(in years)	(in millions)
Balance as of December 31, 2015	8,443		$	7.10
Stock options exercised	(501	)	3.63
Balance as of March 31, 2016	7,942		$	7.32	3.5	$	848
Stock options vested and expected to vest as of March 31, 2016	7,941		$	7.32	3.5	$	848
Stock options exercisable as of March 31, 2016	5,984		$	5.54	3.2	$	650


(1)	The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock option awards and the official closing price of our Class A common stock, as reported on the NASDAQ Global Select Market, of $114.10 on March 31, 2016.

The following table summarizes the activities for our unvested RSUs for the three months ended March 31, 2016:



	Unvested RSUs⁽¹⁾
	Number of Shares		Weighted Average Grant Date Fair Value
	(in thousands)
Unvested at December 31, 2015	116,409		$	65.95
Granted	20,498		110.03
Vested	(14,238	)	57.78
Forfeited	(1,053	)	64.67
Unvested at March 31, 2016	121,616		$	74.34


(1)	Unvested shares include inducement awards issued in connection with an acquisition in 2014 and are subject to the terms, restrictions, and conditions of separate non-plan RSU award agreements.

The fair value as of the respective vesting dates of RSUs that vested during the three months ended March 31, 2016 and 2015 was $1.45 billion and $814 million, respectively.

As of March 31, 2016, there was $8.67 billion of unrecognized share-based compensation expense, of which $8.19 billion is related to RSUs and $478 million is related to restricted shares, shares with performance conditions related to our contingent consideration, and stock options. This unrecognized compensation expense is expected to be recognized over a weighted-average period of approximately three years.