All three major U.S. stock indexes posted record closing highs again Tuesday as Nvidia shares gained following news it will build artificial intelligence supercomputers for the U.S. energy department, and as investors were optimistic about corporate earnings ahead of key results from megacaps this week.

Nvidia's CEO, Jensen Huang, said the company will build seven supercomputers for the U.S. Department of Energy, and said the company has $500 billion in bookings for its AI chips. Nvidia also announced new details with Finnish telecom equipment maker Nokia to target the AI communications market.

Microsoft's shares also gained after the company reached a deal that allows OpenAI to restructure into a public benefit corporation while giving Microsoft a stake of 27% in the ChatGPT maker.

Key quarterly results are expected this week from Apple , Microsoft, Alphabet, Amazon, and Meta Platforms. Investors are anxious for details from the companies on AI spending. "Momentum and earnings are pushing the market higher," said Peter Cardillo, chief market economist at Spartan Capital Securities in New York, adding that there is also "enthusiasm about Trump's Asian trip."

"Earnings have been good," he said. "Of course, we're waiting for the big tech stocks." Trump lavished praise on Japan's first female leader, Sanae Takaichi, in Tokyo on Tuesday. They signed a deal to bolster supplies of critical minerals and rare earths, as their nations seek to reduce China's dominance of some areas of key electronic components.

According to preliminary data, the S&P 500 gained 15.79 points, or 0.24%, to end at 6,890.95 points, while the Nasdaq Composite gained 190.04 points, or 0.80%, to 23,827.49. The Dow Jones Industrial Average rose 162.06 points, or 0.34%, to 47,706.65. United Parcel Service shares rose after it forecast fourth-quarter revenue above expectations. Rival FedEx also gained.

QUARTERLY EARNINGS UP

Third-quarter earnings for S&P 500 companies are estimated to have increased 10.5% from the year-ago period, up from earlier estimates for the quarter, according to LSEG data.

The Federal Reserve is widely expected to announce this week a cut in interest rates. Investors will be keen to get any details on the rate outlook, especially given that the U.S. government has been shut down for nearly a month, delaying crucial economic data and forcing traders to rely on private releases and corporate announcements.

A preliminary estimate of an ADP National Employment Report showed the U.S. economy added an average of 14,250 jobs in the four weeks ending October 11.