The U.S. stock market has gone taken a nosedive since President Donald Trump announced tariffs for many countries around the world. Here's what to know.

Then again, with the stock market entering 2025 at its third-priciest valuation in 154 years, and Trump inheriting the priciest market of any president, this double-digit percentage move lower for the S&P 500 and Nasdaq Composite is, perhaps, not all that surprising.

Financial markets often overreact, but this Trump slump is perfectly rational and explicable. Tariffs are taxes on goods, and imposing them reduces over-all buying power in the economy. On Friday, Jerome Powell,