If the price drops , even now at 90 , if he buys back he will get more BTC than he had and he can play his card better.
Now , if he keeps this game with 2 drops and then one buy a few times undisturbed he will slowly gain more influence ....
Of course we add around 3500 coins daily to compensate this , but, still an unhealty scenario.
A guy with enough bitcoins who is in only for gains , enough power to influence the price... sounds like a .. central b***.
If it's the same guy who dumps every sunday i don't see him buying anything back. He's getting out and depending on how many coins he has this could go on for a while.
You could think he does it on sunday morning to cause as little panic as possible.
If he was after a price drop to buy back more i'm pretty sure he would do it differently.