Hello, I have a question regarding initial and maintenance margin for futures trading. Let's take the e-mini S&P 500 as an example. If I want to hold my position overnight, I understand the margin is more than if I just day traded - opened and closed my position the same day. The margin for holding a position overnight is $5,625 for initial margin and $4,500 for maintenance. Here's where I'm confused. Do I need $5,625 to open a position (1 contract) and also $4,500 to stay in my account to hold the position overnight, which would make the total required to trade 1 contract overnight $10,125? Or do I just need $5,625? That's where I'm confused. How is the $4,500 accounted for?