Some investors don't ever sell a stock .One of the golden rules of wall st. is to take profits on the way up with a winning stock . Insiders are doing just that. If Mark Zuck. sells one year from now,or ipo date? will he sell all,or some maybe none. The stock looks very nice- @100-200,or more. Don,t forget those splits on the way up. looking back from 100.- 200 will make 25.00 look very small.