What if: an old hand dumps all their coins right now?

[JanpriX]

You have quite a proposition here and this is very possible in every aspect that you said in your post. But, I don't think that someone in their right mind will do that especially with the price that we have right now. They might sell some of it but will not do it from all of their stack of BTC. Their right move would be sell some while the price is climbing and wait again for the right time if the price goes down.