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.