Utilize your financial knowledge, give your answer or opinion to the input question or subject . Answer format is not limited.

What should I invest in to hedge against a serious crash or calamity?
Different risks require different hedges.  You won't find a single hedge that will protect you against any risk.  The best way to think about this is who would benefit if those events occurred?  Those are the people you want to invest in.  So if a war broke out, who would benefit?  Defense contractors.  Security companies.  You get the idea. You also need to think about if you really need to hedge against those things now or not.  For example, I wouldn't bother to hedge against global warming or peak oil.  It's not like one morning you're going to wake up, turn on CNNfn and see that the stock market is down 500 points because global warming or peak oil just hit.  These are things that happen gradually and you can react to them gradually as they happen.