Stock mkts tend to overreact when there is war. War can result in mispricing of stocks and provide opportunities for the discerning and astute investor to buy undervalued ones. Timing will be important. If the war is likely to be shortlived because the countries involved are unevenly matched or only two small ( as in economic importance such as world trade or population or geographic size) countries are fighting, a rebound will be quick and one should not hesitate to act. If not such, one should wait for a bottoming. Honing of stock selection eg choosing stocks positively impacted such as energy, commodities etc can enhance investment returns.