Stock sales are kinda weird when youre talking about large sales like that, because some will hit the dark pools making them less likely to affect the price.
However, that is usually reserved for institutions, not private sales.
On top of that, youd have to assume that only one sale would occur, and he wouldnt need to piecemeal his transactions by selling blocks of shares instead of the whole lot.
Its really tough to predict, but id like to imagine nobody even wants his POS company.