Imagine one is long, say 30 ES (that's ~$1,650,000.00 worth of S&P futures) and the Bad Guys nuke New York and Chicago, and Globex halts for 4 weeks. It finally reopens down 500 points (a tad less than -50%). That's a loss of $750,000.00 AKA three quarters of a million. Now the daily margin to trade ES is ~2k at IB. So one could have an account of only 60k and be short 30 contracts. Then owe $690,000.00 in addition to their account, most likely wiping one out entirely. So that makes me wonder if it's worthwhile to buy some ES (or other?) contracts to cover one's butt in case of emergency. One could incorporate that as a cost of doing business. And one would be insured upside and down. Seems worth considering. I have no idea about the cost tho.