Key Takeaways The S&P 500 is off to its worst start for a presidential term since 2009, when Barack Obama entered the White House in the midst of the global financial crisis.Traditionally defensive sectors have outperformed since Trump's inauguration amid growing concern that tariffs could usher in a period of stagflation.

As major indexes slide and investors worry, the president abandons his longtime claim that Wall Street performance is the only economic metric that matters, and digs in on import tariffs most businesses oppose.