Let's say you were long an unhedged stock portfolio on 9/11/01 (as many of us were). After the US markets were shutdown, what would have been some ways to hedge? Were any markets open in the world? And if so, how would you even be able to buy or sell on them? P.S. I don't mean to minimize the tradgedy of that day. I had some friends who made it out "safely" and one who didn't.