system
A chat on subreddit /r/wallstreetbets
human
You can get margin calls for other reasons besides maintenance, but you're guaranteed to get a margin call if the amount you've contributed towards the value of the account ever dropa below 25%

gpt
Makes sense but ... that's weird? Like if you put £200 in and it rose to £2m overnight... where are you gonna get 250k from? The broker shutting your positions down could actually cost you... can't you sell off to get the gains and then re-invest to effectively put more money in?