Let's say I have 10k USD in my margin account. I place 100 round trip orders in a single day, each worth 2000 USD (999 USD buy order and 1001 USD sell order).
How much margin did I use at the end of the day? Can I do as many 2000 USD round-trips a day as I like?
I am trying to understand how I can do frequent day trading without running into an issue with unsettled funds. I am interested in an answer both relating to stock and forex trading, and any other instrument that settles instantly or otherwise allows me to trade 100s of round-trips each day.