system
A chat on subreddit /r/wallstreetbets
human
&gt; Robinhood financials and/or RHS can increase its respective 'house' margin maintenance requirement at any time and is not required to provide you advance written notice 
  
 Like wtf... Is this even legal?

gpt
Yes. Every broker does that. Regulations define the minimum margin requirements (ie, max leverage) but the broker has the possibility to increase margins to manage their risk.