Entire sectors of the global economy are in turmoil after Russia’s invasion of Ukraine, leaving investors worried about how they should react. Should they buy energy stocks? Shares of defense contractors? What about agriculture? Is it time to go to cash?Investors had good reason to be wary even before President Vladimir V. Putin of Russia invaded. First-quarter market forecasts predicted tepid gains of less than 5 percent for the S&P 500. A report from the financial data company FactSet Research noted that such a sluggish level of growth would be the lowest since the fourth quarter of 2020.Instead, the S&P 500 finished down for the quarter, losing 4.9 percent. Inflation fea …
