Ever since Donald Trump returned to the White House in January, stock market expectations have been volatile – driven in part by a healthy dose of motivated reasoning. At first, markets surged on hopes of lower taxes and deregulation. But this enthusiasm soon faded as announcements about tariffs and stricter immigration policies dampened sentiment. Underscoring that point, on March 3, the Dow Jones Industrial Average fell more than 600 points after Trump said that tariffs he had been threatening for weeks would indeed be imposed on Canada and Mexico the following day. In all of these cases, investors weren’t just…