Taking the original question seriously, at least a little.
Suppose one small nuclear bomb goes off in the US, devastating part of a major city. Also suppose you are not directly affected by the blast or radiation. Then, as I see the OP's question: What's the US/world economy going to look like in this future? Far more intrusive security, intensive policing, military buildups. Roadblocks to international travel and trade. So -- invest more in military and security stocks? Less in international?
If a large scale nuclear attack happens, the financial world is screwed, and that is the least of your worries (living near DC, I'm mostly likely dead after a large scale attack). Even in the small scale case, a few weeks worth of food and water purifiers might be necessary, as the supply chain may break down for a little while as the nation grapples with the ripple effects of a disaster.
A lot depends on the scenario. Historically, what would you have wanted to hold before WW1, say? Spread your wealth around amongst various countries, hoping that you'd own something in a victor? So who will be the (relative) victor after your chosen scenario? Maybe the right to emigrate to Australia would be the most valuable thing you could own.