Is it legal for US citizens to trade with prop firms based outside the US?
Nope. Lots of people from USA use FTMO and they are based in Prague.
What makes it illegal?
Sorry, yes it’s legal. I thought you asked if it was illegal, my bad.
Ok, thanks 
Is it legal for US citizens to trade with prop firms based outside the US?
Nope. Lots of people from USA use FTMO and they are based in Prague.
What makes it illegal?
Sorry, yes it’s legal. I thought you asked if it was illegal, my bad.
Ok, thanks