CNBC Daily Open: Downgrade of U.S. credit rating adds new complication to U.S. stock market

U.S. stocks popped last week on the back of a trade truce between America and China, in which they mutually agreed to cut tariffs for 90 days. Technology stocks soared, with Tesla and Nvidia leading the pack. Absent new developments on the tariff front, however, it's unclear if this buoyant sentiment can last.

For one, the U.S.' credit rating was downgraded by Moody's Ratings to the second highest. This means investors could demand higher returns for U.S. Treasurys amid their ostensibly lower trustworthiness. Rising Treasury yields, in turn, could pressure stocks. Even though Moody is merely the latest to join Standard & Poor's and Fitch Ratings in bumping down the U.S. from the top rating — which did so in 2011 and 2023 respectively — it might send another crack through an already fragile stock market.

Although Nvidia was one of the winners of last week's rally, it is still contending with chip export restrictions to China and increased scrutiny over its business activities. That's a big deal because China's artificial intelligence sector is "not behind" that of the U.S., and will probably reach around $50 billion within three years, according to Nvidia CEO Jensen Huang. Losing out on that market would be a "tremendous loss," he added.

Whether last week's rally can be sustained will rely, then, on the headlines that will come from the White House this week.

Moody's cuts U.S.' credit rating
Moody's Ratings cut the United States' sovereign credit rating down one notch to Aa1 from Aaa, which is the highest possible, citing the growing burden of financing the federal government's budget deficit and debt. Treasury Secretary Scott Bessent on Sunday called the downgrade a "lagging indicator," claiming it reflects conditions during the Biden administration.

Winning week for U.S. stocks
All major U.S. indexes rose Friday. For the week, the S&P 500 surged 5.3% and the Dow Jones Industrial Average climbed 3.4%. The Nasdaq Composite popped 7.2% on the back of strong showings from technology stocks such as Tesla and Nvidia, which jumped 17% and 16% respectively on the week. U.S. futures slipped Sunday evening. Europe's regional Stoxx 600 added 0.4% Friday. Shares of Richemont jumped 7% after the Cartier owner posted better-than-expected fiscal fourth-quarter sales, in a sign wealthy consumers are still spending on luxury.

Nvidia denies sending chip designs to China
Following a report in the Financial Times that Nvidia is working on a research and development center in Shanghai in light of new U.S. export curbs, the chipmaker told CNBC it is "not sending any GPU designs to China to be modified to comply with export controls." A source familiar with the matter told CNBC that the company is leasing new space for current employees, but is not sending any IP or GPU designs there.

Trump says he will broker peace
U.S. President Donald Trump said Saturday in a post on Truth Social that he plans to speak separately to Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskyy on Monday in an effort to reach a ceasefire between the two countries. America is also working with Britain to establish an India-Pakistan ceasefire alongside "confidence-building measures" and dialogue, U.K. Foreign Minister David Lammy said on Saturday.

Biden diagnosed with prostate cancer
Former U.S. President Joe Biden on Friday was diagnosed with an "aggressive" form of prostate cancer, his office said on Friday. "The cancer appears to be hormone-sensitive which allows for effective management," his office added.

[PRO] Retail earnings in focus this week
Stocks rallied last week as investors cheered the White House's deal with China to reduce tariffs on each other. This week, keep an eye out on earnings from Home Depot, Target and  TJX for an indication of how the American consumer has been holding up — and how those big retailers will deal with tariffs.

Big Chinese companies like Alibaba show that AI-powered ads are giving shopping a boost

Alibaba, Tencent and JD.com reported earnings this week that not only reflected improving Chinese consumer spending, but also the growing benefits of artificial intelligence in advertising.

AI is helping Tencent lift its click-through rates — a measure of success for online ads — to nearly 3%, company management said on an earnings call Wednesday, according to a FactSet transcript. That's up sharply from a 0.1% click-through rate for banner ads historically, and around 1% for feed ads, the company said.

JD.com said its marketing revenues climbed by 15.7% to 22.32 billion yuan for the quarter, also partly attributing that rise to AI tools.

Lastly, Alibaba noted that marketing revenue, which it calls "customer management," grew 12% year on year to nearly $10 billion, thanks in part to increased use of the company's AI tool, Quanzhantui, for boosting merchants' marketing efficiency.