[tourist_]

I am not a U.S. person, but isn't/shouldn't there be a set of rules for the provider of a brokerage account. Sure, its their house, their rules, but how can they change the rules overnight? If what Robinhood did isn't illegal, then I suppose I had the wrong impression about the strength of financial regulations in the U.S. (If this happened in my home country, I would never participate in the markets again.)

[TameAntelope]

I think what we're finding out now is that this happened as a result of the strength of financial regulations/safety systems in place in the US markets.

Volatility increases risk, and higher risk requires higher levels of safety to operate properly, and Robinhood couldn't provide the higher level of safety, so they were given no choice by the people who actually execute their trades.

In the coming days, more information will add context that, I expect, will make the populist outrage look foolish/uninformed. In many ways, we're already there.