Eh, if I did this and I came up in the black off on a play with $1M in free leverage I would just close the position, pay off the margin and dip without posting about it. If like five people posted about it and lost money, there are probably a couple winners who are lying low, even just completely randomly assuming the traders have absolutely no signal whatsoever in their choice of play.
RobinHood is essentially lending unlimited money to the teenagers in question. Assume, as an oversimplification, half of them will win big, and half of them will lose it all.
For the wins, the teenagers will keep it all, and for the losses, RobinHood will have to pay for it, because the teenagers don't have the money and will declare bankruptcy if RobinHood tries to recover it. This is a net wealth transfer from RobinHood to the teenagers.
The net wealth transfer looks like this:
teenagers: +lots of money
traders on the other side of the transactions: approximately +0 (wins and losses cancel out)
RobinHood: -lots of money
You can play games with which money comes from where, but you can't deny the way the money is flowing on net.
