A busy stock market week bookended by DeepSeek and Trump tariffs, by the numbers

News from China upset U.S. markets this week and disrupted the frenzy that had built up around artificial intelligence.

A company called DeepSeek announced that it had developed a large language model that can compete with U.S. AI giants but at a fraction of the cost. DeepSeek had already hit the top of the chart for free apps on Apple’s App Store by Monday morning, and analysts said such a feat would be particularly impressive given how the U.S. government has restricted Chinese access to top AI chips.

Chipmakers incurred some sizeable losses. Still, the noise in the tech sector obscured some solid gains in other parts of the market, such as the consumer discretionary sector, which includes Amazon and Tesla, and the communications sector, which counts Meta Platforms as a member. Cruise lines were also standouts.

The S&P 500 closed the week with a loss of 1%. The market got a slight jolt late Friday after the White House said President Donald Trump would impose promised tariffs on some key U.S. trading partners.

Here's a look the week in the stock market, by the numbers:

The week’s decline in the S&P 500 tech sector, the biggest drop in the index in about four months. Big losses for chipmakers like Nvidia, Micron Technology and Broadcom weighed down the index. The decline would have been worse if not for a solid gain in shares of Apple.

The approximate point drop in the S&P 500 Friday between the time the White House confirmed Trump's decision on tariffs and the close of the market. That's a drop of about 1.2%. Though not a dramatic swing, it does harken back to Trump's first term, when pronouncements on trade policy could bring about rapid change in the direction of the stock market.

The approximate decline in Nvidia’s market value on Monday, a record. The decline was more than the combined market value of home improvement giants Home Depot and Lowe's. Nvidia still carries a market value of just under $3 trillion. The company's billionaire CEO, Jensen Huang, saw his net worth drop by nearly $21 billion Monday.

The weekly decline in Constellation Energy Corp., which isn't a tech company but an independent power producer. Shares of power companies such as Constellation, Vistra and GE Vernova had soared on expectations that the build out of AI infrastructure in the U.S. will require enormous amounts of power.

That's the amount Facebook and Instagram parent Meta Platforms agreed to pay to settle a 2021 lawsuit that President Donald Trump brought against the company and CEO Mark Zuckerberg after Trump’s accounts were suspended following the Jan. 6, 2021, attack on the U.S. Capitol. More importantly for shareholders, Meta reaffirmed its commitment to spending heavily to implement its AI strategy.

The weekly gain for Apple Inc., which ironically may have benefitted from DeepSeek's announcement. Unlike tech peers such as Microsoft, Google corporate parent Alphabet Inc. and Meta, Apple hasn’t been investing as heavily in AI – one of the reasons it has been seen as an industry laggard. But that restraint could work to its advantage if DeepSeek’s early breakthroughs in driving down AI costs gains momentum.

Monday's drop in Oracle CEO Larry Ellison’s net worth after the selloff, according to Forbes Real-Time Billionaires list. Ellison’s net worth jumped last week after President Donald Trump said a new partnership formed by OpenAI, Oracle and SoftBank would spend up to $500 billion for infrastructure tied to AI. Forbes' tally shows Ellison made back about $13 billion of the drop as this week went along and Oracle’s stock recovered.

That's when Royal Caribbean Group, known mainly for its namesake ocean cruises, plans to enter the river cruise market. That news, plus better-than-expected quarterly earnings, helped Royal Caribbean post the biggest weekly gain of any stock in the S&P 500 at nearly 15%.

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This story has been corrected to say that Constellation Energy had a weekly decline, not gain.