Earlier quoted context omitted.
>they will change the rules on you so they win anyway Are you referring to how several popular brokerages prevented customers from opening new positions? That's due to them unable to fulfill deposit requirements on such volatile stocks, not because of some conspiracy by wall st to "change the rules on you so they win anyway". see: https://www.bloomberg.com/opinion/articles/2021-01-29/reddit... , under heading "Why di…
I guarantee you the interests of institutions on the short side of the stock factored in to the decision to raise deposit requirements. And the Interactive Brokers chairman is explicit about why he chose to block buys.
Is there any evidence for this, other than the general feeling of "rich people are powerful, therefore they must have been some meddling by them"? The formula for determining the deposit requirements is publicly documented: https://twitter.com/kralctrebor/status/1354952686165225478, so the judgement call looks pretty straightforward to make.