This may have more of an impact on Robinhood's earnings than investors think. Robinhood Markets (HOOD -6.18%) stock has crushed it for the last year. The online brokerage that revolutionized free stock trading is up 100% in the last 12 months, compared to 27% returns for the S&P 500 index. The company just reported strong growth across the board in the first quarter of 2024 and is finally generating healthy amounts of profits. But there is something looming above Robinhood's business, and it could be an imp ...