It's a short squeeze, not a pump and dump, as you describe. In a short squeeze, the hedge funds that hold the shorts will be the ones who lose money. Although,

It's a short squeeze, not a pump and dump, as you describe. In a short squeeze, the hedge funds that hold the shorts will be the ones who lose money. Although, to be fair, some gullable speculators probably will too, but the point is to make money off the hedge funds' poor trade. The SEC can step in for pump and dump schemes, no reason for Robinhood to have taken the initiative (AFAIK).