Looking at the grant price I infer that their options might be approaching expiration. Also all sales are automatic, it hit certain parameters and the transaction got executed. It is a combination of their smartness and luck that fetched them such decent returns. It gives me comfort to invest in CTSH with these guys managing the company!
In my honest opinion, I think that they are taking some short term profits for a temporary correction. This correction is a reflection of a weakening economy and some socialist tendencies from the Democratic party. Once the pro-business GOP rides in, and all the protectionist, Marxist anti-outsourcers are purged, I think that CTSH will start to trend up again.