Quarterly stock shares for senior management vesting per the company agreement dated as below. I snagged this statement from CSO Peter Lamb's SEC form 4...but they all read pretty much the same...check out the dates. Just like clockwork...right on schedule.
"On December 15, 2009, the reporting person was granted 12,500 restricted stock units, of which 1/16th of the shares subject to the restricted stock units vested on February 15, 2013. The common stock into which such vested restricted stock units converted on February 15, 2013 is reported in Table I on this Form 4. The remaining unvested restricted stock units will continue to vest as to 1/16th of the original number of shares subject to the restricted stock units on each succeeding May 15, August 15, November 15 and February 15 until fully vested. "