Like if I'm fishing, I might not catch a fish that day, but if you collapse the pier I'm fishing from then you've concretely caused particular harm to my chances of catching a fish?
Answering this sort of question likely requires digging through cases at the district and circuit court level to find people who made this kind of argument, and seeing if the court bought it or not. I'm not paid to do that, and the people who are are paid big bucks to do so.
But my suspicion is that you have to draw a pretty strong link between the actions of the defendant and your losses, to the point that you really no had other option than to eat the losses. In the case of the pier collapse, you might be able to swing that if there were nowhere else you could fish from. But in the case of Robinhood, I'd be surprised if you could sustain that argument, especially because you've signed this pesky contract.
Of the stuff I see on court listener:
* 3 don't have documents available (and I'm not going to bother signing up for PACER just to find out)
* 1 has a claim predicated on "I could have bought or shorted GME" (yeah, not gonna fly)
* 1 has a claim predicated on "the value of GME stock fell, causing me loss" (doesn't mention if the stock was actually sold, so it's purely paper loss, so really not gonna fly)
* 1 has a claim predicated on "I tried to buy, but couldn't" (best chance of succeeding, but I think they're still screwed anyways)
It's a good message board power-up, I guess.
Much of the nice and fast experience that Robinhood offers ("Just signed up? You can start trading!", "Initiated a transfer? Start trading now!", "Just sold something? Rebuy something else immediately!") are all powered by the fact that these are all technical using margin.
"I intended to buy at a higher price in order to manipulate the price of an asset well above its value, and was harmed by being delayed until a later time where I could buy it at a lower price" -- not going to fly.
If RH is inadequately disclosing the risks of margin trading then some of their customers that had positions closed due to margin requirements might have cases.
"I was harmed because I was delayed from buying at a higher price and instead could only buy at a lower price later!" -- only being able to buy at a lower price later is only a "harm" in the sense that it prevented price manipulation.
This is an easily quantifiable and concrete claim that might be brought up by every Robinhood user with cash in their account.
They would be safer if the stock had continued to drop.
Very probably. The general principle of Article III jurisprudence is that you have to demonstrate concrete, particularized harm to bring a case, not generalized, theoretical harm.
If your allegation is that your harm arises from "I could have made a killing if I bought and sold the stock at appropriate times," well that is theoretical harm (especially when you undercut buy alleging that you could have done so on other platforms). You'd probably have to allege that you attempted to buy (alternatively, sell) the stock and Robinhood prevented you from doing so, but the fact that you signed a contract saying that you acknowledge that Robinhood can prevent you from being certain stocks is going to be a challenging hurdle to overcome.