Interactive Brokers offers the margin account for IRAs. There are certainly rules investors have to follow. Since I do not have such account and just wonder how it works. I know I can't borrow $. How about day trading? Say I have $20k in cash. If I buy stock that is worth close to that amount, I think I should be able to sell the same day. I'm not sure if I can do any more trades the same day. I believe I can only do one trip on that day. With the cash account, I may have to wait until the settlement day, which is T+3. What else can you do with IRA margin account?