Congratulations, you just bought on margin!
Margin = Asset Value - Loan Value
Margin = $1M - $800K
Margin = $200K
Otherwise, he will be forced to seize the collateral (your Nicaraguan beachfront land!) and walk away.
This was a “margin call” (literally and figuratively!).
Never trade on margin if you are going to be in financial distress if you get margin called!
So that’s a simple primer on the topic. I hope it was helpful!