Stockholders' Equity and Stock-Based Compensation |
(2) Stockholders Equity and Stock-Based Compensation
During April 2009,April 2008, and April 2007, the Compensation Committee of our Board of Directors approved the grant under our employee stock option plan, effective at the close of business that day, of options to purchase approximately 395thousand shares, 275thousand shares, and 2.2million shares, respectively, of our common stock.
On April20, 2010, the Compensation Committee of our Board of Directors approved the grant under our employee stock option plan, effective at the close of business that day, of options to purchase approximately 265thousand shares of our common stock at a strike price of $60.00 per share. The closing stock price on the date of grant was $54.19 per share.
All of the options noted above vest and become exercisable over a period of up to eight years. Each option will terminate, to the extent not previously exercised, 13 months after the end of the relevant vesting period. As of March31, 2010, options granted in April 2007 had vested with respect to approximately 210 thousand shares. No other options were vested as of March31, 2010.
Compensation expense equal to the grant date fair value will be recognized for all of these awards over the vesting period. The stock-based compensation expense for the three month periods ended March31, 2010 and 2009 was $1,000 and $900, respectively. Unrecognized compensation expense related to outstanding stock options as of March31, 2010 was $16,585 and is expected to be recognized over a weighted average period of 6.021 years. Any future changes in estimated forefeitures will impact this amount.
The fair value of each share-based option outstanding as of March31, 2010, is estimated on the date of grant using a Black-Scholes valuation method that uses the assumptions noted in the following table. The expected life is the most significant assumption as it determines the period for which the risk-free interest rate, volatility, and dividend yield must be applied. The expected life is the average length of time over which the employee groups will exercise their options, which is based on historical experience with similar grants. Expected volatilities are based on the movement of the Companys stock over the most recent historical period equivalent to the expected life of the options. The risk-free interest rate is based on the U.S. Treasury rate over the expected life at the time of grant. The dividend yield is estimated over the expected life based on our current dividend payout, our historical dividends paid, and our expected future cash dividends. The following table illustrates the share price information and assumptions used to determine fair value:
Options Granted
April 2009 April 2008 April 2007
Strike price $ 54.00 54.00 45.00
Closing market price on date of grant $ 35.22 48.70 40.30
Weighted-average expected life of option in years 5.0 5.0 4.9
Weighted-average volatility 38.8% 30.7% 31.6%
Risk free interest rate 1.9% 2.7% 4.6%
Expected dividend yield 1.0% 1.0% 1.0%
Weighted-average gra |