I think a broker or marketmaker has in the order of minutes to bust a trade that is "clearly erroneous" and it has to be immediately reported. The exact time p

I think a broker or marketmaker has in the order of minutes to bust a trade that is "clearly erroneous" and it has to be immediately reported. The exact time period varies by exchange but for example for nasdaq it's 30mins for some trades and 60mins for others https://nasdaqtrader.com/Trader.aspx?id=ClearlyErroneous https://nasdaqtrader.com/Trader.aspx?id=ClearlyErroneous For the exchanges I'm more familiar with (in Europe) it's less. The criteria for clearly erroneous trades are incorrect price, size or security though so I don't think this would qualify. Most likely scenario here is that there is an investigation into fraud and that any gains here get forfeit but users are still required to make good any losses. Separately I would expect RobinHood gets a hefty fine as well.