Those that do what he says.  He gets their coins.

Pretty simple scheme he has going.

1) He buys coins cheap prior to announcing his pump.
2) He announces what time his pump is going to be.
3) Dumbasses flock to that coin and buy it up, thus driving the price up.
4) He immediately dumps all of his cheap coins on top of the dumbasses, thus dropping the price like a rock.
5) He profits, they lose.