Wall Street's three main indexes touched record highs again Tuesday, with the Nasdaq gaining the most thanks to boosts from Microsoft and Apple in a week packed with earnings from U.S. heavyweights.

Microsoft jumped 2.8% after reaching a deal that allows OpenAI to restructure into a public benefit corporation while giving Microsoft a stake of 27% in the ChatGPT maker.

Apple shares crossed $4 trillion in market value for the first time earlier in the day, hitting a record high before easing to trade flat. Strong demand for the latest iPhone models have allayed fears over its slow progress in the AI race.

Megacaps Microsoft, Alphabet, Apple, Amazon and Meta are scheduled to report results later in the week with investors scrutinizing any AI-related updates to justify high valuations and hefty investments.

On Tuesday, global economy bellwether United Parcel Service climbed 7.6% after forecasting fourth-quarter revenue above Wall Street expectations. Rival FedEx added 1.4%.

Of the 143 companies in the S&P 500 that reported earnings last week, around 87% beat analyst estimates, according to LSEG data.

"The earnings are coming in much better than expected and the guidance is actually coming in fairly good as well, and that's helping support the market during the government shutdown and all the tariff talk," said Robert Pavlik, senior portfolio manager at Dakota Wealth.

At 11:50 a.m. EST, the Dow Jones Industrial Average rose 150.75 points, or 0.32%, the S&P 500 gained 0.11 points, or 0%, and the Nasdaq Composite gained 76.45 points, or 0.32%.

The S&P 500 tech index led gains, with AI bellweather Nvidia adding 0.9% after U.S. President Donald Trump said he would meet CEO Jensen Huang.

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.

Wall Street futures had moved higher after 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.

Investors also scrutinized layoff reports from companies including Amazon, Paramount and United Parcel Service.

Fed officials will meet later in the day to discuss interest rates and plans to end the central bank's "quantitative tightening" policy. Its verdict on interest rates is due to be announced on Wednesday.

Markets are now pricing in expectations that the U.S. central bank will lower borrowing costs by 50 basis points by the year-end.

Among others, UnitedHealth raised its annual profit forecast. Shares were last flat in choppy trading.

PayPal surged 10.6% after it announced a partnership with OpenAI to allow ChatGPT users to buy products using the payment firm's platform.

Royal Caribbean Group slid 8.6% after a disappointing fourth-quarter profit forecast. JetBlue Airways shares slumped 12.5% after posting a lower profit for the quarter.

Alexandria Real Estate fell 15.4% after forecasting annual adjusted funds from operations below expectations. That weighed on the S&P 500 real estate index, sending it down 1.8%.

Declining issues outnumbered advancers by a 2-to-1 ratio on the NYSE. Declining issues outnumbered advancers by a 1.87-to-1 ratio on the Nasdaq.

The S&P 500 posted 19 new 52-week highs and 10 new lows while the Nasdaq Composite recorded 42 new highs and 47 new lows.