Quote from greggg:Lets say what I quoted above is the case. What happens if this trade is held over night.
How does the over night margin rate effect it?
Intraday margins are established by the brokerage firm you deal with. The exchanges have no intraday requirements. That's why you'll see ads saying $300 margin per ES contract. That is only for day trading.
Overnight futures margins are established by the exchange at which the future is traded. All US-based brokerage firms must use the overnight exchange-set rates. I believe they can actually exceed them if they wish but I haven't read about this area in a while. Exchanges adjust the margin based on calculated risk using a method called SPAN (SPAN refers to Standard Portfolio Analysis of Risk Performance). See this link for IB's very conservative approach :
http://individuals.interactivebrokers.com/en/trading/marginRequirements/margin.php?ib_entity=llc
At the moment GLOBEX (CME) has a $4,500 initial overnight requirement per ES contract. Using the eight ES contract example above:
You go long 8 ES @1300. Day margin (not at IB) = $500 x 8 = $4,000. Market has gone in your favor by 2 points. You are up 8 x $50 x 2 = $800. It is whatever time your brokerage firm imposes the overnight rates. Your account mark-to-market "cash" value is $5000 + $800 = $5,800. Margin required is $4,500. The firm will liquidate seven contracts leaving you with an overnight cash balance of $1,300 and one contract or issue a margin call for an additional $30,200 and keep all eight. Your account would probably be frozen the next day until the margin call was satisfied. I'm not sure what discretion a commodities broker has in this regard. Assuming no margin call allowed, you can see that if your position was down by 2 points all eight contracts would be sold as you would have $4,200, not the $4,500 to satisfy the overnight requirements for just one contract.
Please note - I've only been trading Index Futures for about three years and always with IB. As a result I'm not really up on the CFTC rules. IB makes up their own rules as they go! Since they are conservative, and I trade conservatively, I've never really looked into how other brokers handle the futures "Performance Bond" issue. If you've traded stocks you've probably noticed that "margin" in futures is not what you were used to in stocks. Stock margin requirements are conservative as you have to put up 50% of the value to open a position. In futures like the ES you put up (overnight) $4,500 to carry a 1300 X $50 = $65,000 position.
Perhaps someone with a different broker can explain how it works there. IB never issues margin calls, they auto-liquidate in near real-time.
Jack