Now you're talking about S&P e-minis? LOL. First of all, That risk will be born by the stupid brokerages that offer that kind of DAYTRADE margin and don't have safeguards in effect. BUt they do, I'm sure. If your position drops 2.5 points, they'll probably liquidate your position. Those brokerages, if you notice, say nothing about a margin call. And that's b/c they won't call you for margin, they'll just liquidate your position. Secondly, The S&P doesn't have nearly the volatility that currencies do either on an intraday or daily basis. So the probabilty of an account going negative trading S&P e-minis is remote. Thirdly, there aren't any cross margining setups possible with the E-mini like there is in spot currencies. Eur.usd, Jpy.eur, usd.jpy, etc, that can easily wreak havoc given their correlation on margin should the positions go awry .
Ddunbar, 5 % spike in the S&P in a few seconds http://money.cnn.com/2001/01/03/markets/markets_newyork/ How many people went debit you think with 500 $ margins? Now you show me a situation in Forex with such a spike !!! What is the biggest spike in % you can find, I am waiting...
Ddunbar, If IB was really concerned about debit situations they would just need to increase the margin requirement and not limit the trade size, we still haven't had our answer from Steve regarding "unethical" trades...