Wall Street's main indexes closed higher on Monday, lifted by Nvidia and other AI-related stocks, while steelmakers surged after U.S. President Donald Trump said he would impose additional tariffs on steel and aluminum imports.

Trump's latest potential trade barrier escalation came on Sunday when he said he would introduce 25% tariffs on all U.S. imports of steel and aluminum, on top of existing duties on the metals.

U.S. metals producers that would benefit from steel and aluminum tariffs rallied. Nucor (NUE.N), U.S. Steel (X.N) and Steel Dynamics (STLD.O) rose more than 4% each. Cleveland-Cliffs (CLF.N) jumped 18%, Century Aluminum (CENX.O), opens new tab rallied 10% and Alcoa (AA.N), opens new tab rose about 2%.

AI chipmakers Nvidia (NVDA.O) and Broadcom (AVGO.O) climbed 2.9% and 4.5%, respectively. Amazon (AMZN.O) gained 1.7%.

"Investors are basically saying, 'Hey, let's go back into the areas that worked.' And one reason that investors are optimistic, in my opinion, is because of earnings," said Sam Stovall, chief investment strategist at CFRA Research.

Tesla (TSLA.O), opens new tab ended down 3% after the Wall Street Journal reported that a consortium of investors led by Tesla CEO Elon Musk is offering $97.4 billion to buy the nonprofit that controls artificial-intelligence startup OpenAI.

With fourth-quarter reporting season over halfway through, S&P 500 companies are expected to have posted year-over-year earnings growth of 14.8%, up from expectations of less than 10% at the start of 2025, according to LSEG I/B/E/S.

Expectations for the Fed's rate cuts to stay on hold in March solidified after Friday's mixed U.S. employment report.

Advancing issues outnumbered falling ones within the S&P 500 (.AD.SPX) by a 1.3-to-one ratio.

Across the U.S. stock market (.AD.US), advancing stocks outnumbered falling ones by a 1.9-to-one ratio.