The S&P 500 Index is flirting with the first drop below the 200-day trendline since 2023. The macroeconomic backdrop has been shifting quickly under investors’ feet. President Donald Trump’s multi-front trade war is sowing widespread uncertainty. The combination of higher prices from tariffs could cause US shoppers to retrench, says Julian Zelizer. The president can revive markets in the back half of the year by turning investors’ focus to tax cuts and deregulation, he says. But there are plenty of risks, including the risk of inflation and a slowdown in consumer and business spending, Zelizer says, and a lack of political consensus on the issue of tax cuts for the wealthy and middle class in the U.S. and abroad. The most important wildcards may be the bond market and the most important of volatile markets may be volatile markets and wildcards, says Zelizer, and it’s far from clear that Trump will be able to halt a slump in stock prices once it’s underway, even if the past couple of years have been demonstrably underway.