Quote from giggollo:
How do you guys deal with the uncertainty of getting "overfilled"? Suppose my firm extends to me 30:1 for order placement and 10:1 for actual positions. If i place 30:1 worth of orders (15:1 long, 15:1 short) and then end up getting filled on for every stock (either short or long) ie higher than expected fill rate on this particular day, then i would be facing a potentially large daytrading margin call (now would be holding 15:1 worth of positions right after the open). Of course i could play it safe and envelope with 20:1 only so that even if i get filled on every stock i will be within 10:1, my allowed buying power for actual positions. How do you deal with this issue? Do you ever consider the possibility of getting filled on all stocks, and what kind of margin call you would get in that unlikely scenario?
You could cancel your outstanding orders once you reach your BP limits, but the downside of that is that some of the best OPG's open late.
