Stocks fell deeply on Tuesday as market optimism soured in the wake of increased tariff threats from President Donald Trump on countries who oppose the sale of Greenland to the United States. Those losses led Wall Street to post its worst one-day performance since October.

The Dow Jones Industrial Average (DIA  ) dropped 870 points to end the session below the 49,000 threshold at 48,488.59, while the broader market S&P 500 Index (SPY  ) lost 2% to close at 6,796.86. The tech-heavy Nasdaq Composite (QQQ  ) also sank over 2% to settle at 22,954.32.

Impacting investor sentiment, Trump announced in a Truth Social post on Saturday that Denmark, Norway, Sweden, France, Germany, the United Kingdom, The Netherlands, and Finland will be subject to a 10% tariff on all goods imported into the U.S. starting Feb. 1 "until such as a Deal is reach for the Complete and Total purchase of Greenland." Trump added that those tariffs will increase to 25% starting June 1 if a deal is not reached by then.

European leaders pushed back against Trump's latest tariff threats, with European Commission President Ursula von der Leyen stating that the European Union and the United States have already reached a trade agreement last July.

"In politics as in business --- a deal is a deal," von der Leyen said at the annual World Economic Forum meeting in Davos. "We consider the people of the United States not just our allies, but our friends. And plunging us into a downward spiral would only aid the very adversaries we are both so committed to keeping our of the strategic landscape."

Trump, who is set to speak in Davos on Wednesday, told reporters late Monday that he plans to deliver "a lot of messages," calling is a "very interesting Davos."

The weekend news increased what has been called the "sell America" trade on Tuesday. However, Wedbush analyst Dan Ives said the day's sell-off is an opportunity to buy up key artificial intelligence names like Nvidia (NVDA  ), Microsoft (MSFT  ), Palantir (PLTR  ), and Google (GOOG  ) (GOOGL  ), among others, at a discount.

"The back and forth war of words between Trump and the EU will give investors another opportunity to own the tech winners and despite the bears always trying to yell fire in a crowded theater," Ives, wrote in a note to clients on Tuesday, adding the "the AI Revolution is still in the early days of playing out."

On the earnings front, shares of 3M (MMM  ) sank on Tuesday despite the post-it maker delivering strong fourth-quarter earnings as the company expects tariffs to continue to impact its profits. 3M expects adjusted sales growth of about 4% for its full-year adjusted earnings per share $8.06 in 2026. The company also calls for full-year operating cash flow to be $2.3 billion.

"2025 was an important year for 3M as we build a strong foundation that is reshaping our operating model and driving sustainable value creation," CEO William Brown said in a release.

Looking ahead, all eyes will be on Netflix's (NFLX  ) earnings report after market close on Tuesday. In its fourth-quarter last year, the company posted revenue of $10.25 billion.