Donald Trump’s got the stock market on a string, but investors are less sure of the game he’s playing.

The Republican president’s renewed ramblings on trade dominated U.S. equity markets this week, with a tweet-induced swoon on Friday leaving the S&P 500 Index 1.4 percent lower than where it started on Monday. The gauge swung wildly, notching four moves of at least 1 percent in the five days, and the Cboe Volatility Index spiked above 20, nearly double its level for the past year.