U.S. stock index futures fell on Monday, while Treasury yields rose after ratings agency Moody's downgraded the country's sovereign rating by one notch, bringing forward concerns around the ballooning U.S. debt.

Market Snapshot

At 7:50 a.m. ET, Dow E-minis were down 234 points, or 0.55%, S&P 500 E-minis were down 60.75 points, or 1.02%, Nasdaq 100 E-minis were down 307.75 points, or 1.43%.

Pre-Market Movers

Nvidia - Nvidia declined 3.1%. CEO Jensen Huang announced Monday at the Computex trade show in Taiwan the company would beopening its artificial-intelligence server platformto rival chip makers such as Qualcomm and Marvell Technology. Nvidia also said it would be working with iPhone manufacturer Foxconn to build an AI factory supercomputer in Taiwan.

Tesla - Tesla was down 3.9% in premarket trading. Investors will be monitoring a weekly sales update from China. Recent sales data from the electric-vehicle maker has been disappointing. U.S. sales in April fell about 13% after declining 9% in the first quarter. Sales last month in key European markets, including France, Germany, and the United Kingdom, fell about 49% from a year earlier after dropping about 45% in the first quarter.

Palantir - Palantir Technologies, another popular AI stock, declined 4.6% in premarket trading. It has risen 71% this year and 499% over the past 12 months.

Super Micro Computer - Shares of Super Micro Computer dropped 4.2% in premarket trading. It closed Friday at $46.15, up 5%, but remains down 61% from its all-time closing high of $118.81 on March 13, 2024. The maker of artificial-intelligence servers rose 44% last week.

UnitedHealth - UnitedHealth was up 5.8% in premarket trading after shares of the giant health insurer rose 6.4% on Friday and snapped an eight-session losing streak. However, UnitedHealth declined 23.3% last week after the company’s CEO stepped down, its suspended its 2025 outlook, and a report from The Wall Street Journal saidthe Justice Department was investigating the company for possible criminal Medicare fraud.

Alibaba - The White House and congressional officials have been scrutinizing Apple's plan to strike a deal with Alibaba to make the Chinese company's AI available on iPhones in China, The New York Times reported on Saturday. US-listed shares of Alibaba Dropped 2.2% in premarket trading.

Novavax - Novavax shares surged 17.1% before the bell on Monday, following the long-delayed approval of its COVID-19 vaccine from the U.S. health regulator, albeit with new conditions.

Walmart - Walmart fell 1.9%. U.S. President Donald Trump criticized the world’s largest retailer Saturday, saying the company should “STOP trying to blame Tariffs as the reason for raising prices throughout the chain.” Walmart last week saidthe Trump administration’s tariffs would lead to price increases. The president, in a post on his Truth Social platform, said Walmart should “EAT THE TARIFFS,” and not charge valued customers ANYTHING.” A company spokesman told Barron’s that Walmart would “keep prices as low as we can for as long as we can given the reality of small retail margins.”

JPMorgan Chase - JPMorgan Chase declined 0.8%. The bank, in slides released ahead of its 2025 Investor Day, maintained its net interest income forecast for the full year, reaffirming previous guidance of about $94.5 billion.

Diageo - Diageo, which owns brands such as Johnnie Walker whisky, Guinness beer and Smirnoff vodka, said it expects U.S. tariffs to take a $150 million bite out of its annual profit but it was sticking with guidance for fiscal 2025 and 2026 because mitigation efforts would offset about half of the impact. U.S.-listed shares of Diageo fell 1.1%.

TXNM Energy - Blackstone's infrastructure unit will acquire TXNM Energy in a $11.5 billion deal, including debt, the utility firm said on Monday. TXNM Energy shares jumped 9.2% in premarket trading.

Market News

US loses last top credit rating with downgrade from Moody's

The US was stripped of its last top credit rating by Moody’s Ratings, reflecting deepening concern that ballooning debt and deficits will damage America’s standing as the preeminent destination for global capital and increase the government’s borrowing costs.

Moody’s lowered the US credit score to Aa1 from Aaa on Friday, joining Fitch Ratings and S&P Global Ratings in grading the world’s biggest economy below the top, triple-A position. The one-notch cut comes more than a year after Moody’s changed its outlook on the US rating to negative. The credit assessor now has a stable outlook.

“While we recognize the US’ significant economic and financial strengths, we believe these no longer fully counterbalance the decline in fiscal metrics,” Moody’s wrote in a statement.

Trump Administration Is Concerned by Deal to Put Alibaba's AI on IPhones, NYT Reports

The White House and congressional officials have been scrutinizing Apple's plan to strike a deal with Alibaba to make the Chinese company's AI available on iPhones in China, The New York Times reported on Saturday.

U.S. authorities were concerned that the deal would help a Chinese company to improve its artificial intelligence capacities, broaden the reach of Chinese chatbots with censorship limits and deepen Apple's exposure to Beijing laws over censorship and data sharing, the paper said, citing three people familiar with the matter.

In February, Alibaba confirmed its partnership with Apple to support iPhones' AI services offering in China.

Nvidia CEO Unveils New Technologies to Protect AI Chip Lead

Nvidia Corp. unveiled the latest raft of technologies aimed at sustaining the boom in demand for AI computing — and ensuring that its products stay at the center of the action.

Huang opened with an update on timing for Nvidia’s next-generation GB300 systems, which he said are coming in the third quarter of this year. They’ll mark an upgrade on the current top-of-the-line Grace Blackwell systems, which are now being installed by cloud service providers.

The chipmaker is offering a new version of complete computers that it provides to data center owners. NVLink Fusion products will allow customers the option to either use their own central processor units with Nvidia’s AI chips or use Nvidia’s CPUs with another provider’s AI accelerators.

MediaTek Inc., Marvell Technology Inc. and Alchip Technologies Ltd. will create custom AI chips that work with Nvidia processor-based gear, Huang said. Qualcomm Inc. and Fujitsu Ltd. plan to make custom processors that will work with Nvidia accelerators in the computers.

Trump Tax Bill Passes Key Panel to Advance in US Congress

U.S. President Donald Trump's sweeping tax-cut bill, which had been stalled for days by Republican infighting over spending cuts, won approval from a key congressional committee on Sunday in a rare victory for Trump and House Speaker Mike Johnson.

At an unusual Sunday night session, four hardline Republican conservatives on the House Budget Committee, who had blocked the legislation on Friday, allowed the bill to move forward as they pressed for deeper spending cuts in closed-door talks with Republican leaders and White House officials.

A possible vote on passage in the House of Representatives could take place later this week.