> Robinhood is effectively lending money with little guarantee to take anything back and no source of income. i have not looked into robinhood's margin offerin

> Robinhood is effectively lending money with little guarantee to take anything back and no source of income. i have not looked into robinhood's margin offering, so maybe it's very different, but in my other brokerage accounts, margin works something like this: i buy $10k of SPY. after the trade closes, the broker says "ok, you own $10k of SPY, and that's good for another $5k of margin." so then i can go buy another $5k of whatever i want. i pay 9% interest or so on that $5k. if SPY drops in value "enough", the broker can on a moment's notice, sell as much of the SPY as they want to cover my debts. so... they've got a great guarantee they can take it all back.