The S&P 500 fell 1.4% on Thursday, marking its lowest point of the year and sliding into a market correction, as it is now down 10.1% from the all-time high it reached less than a month ago. The Dow Jones Industrial Average also hit a year-to-date low, closing down 537 points.

Second, the U.S. stock market recovered remarkably quickly from the tariffs imposed during the first Trump administration. Specifically, while the S&P 500 declined 19.8% over a three-month period between September and December 2018, the index had already recouped its losses and reached a new high by May 2019.

President Donald Trump triggered Monday’s stock market sell-off with his shifting tariff policies, which are bad news if they’re tactical and even worse if they’re long-term strategies, market observers said.