To be completely fair, the risk of nuclear war shouldn't be priced into the US equity markets. If a catastrophic nuclear war happens, the only way selling stocks can help you is by excessive short-term spending on frivolous luxuries. The risk/reward profile simply doesn't make sense for even a significant risk to substantially alter investor behavior.
Nope. The market is adaptive, though. Every time someone sells on a piece of news that "should" be ignored, it trains the rest of the market to "buy the dip".
