Happy Friday and happy 2026! I began my year at the movie theater watching an Amanda Seyfried-led movie-musical ("The Testament of Ann Lee," not "Mamma Mia!").

Stock futures are up this morning. The market is on a four-day losing streak.

Here are five key things investors need to know to start the trading day:

Glass half full: The market just wrapped up another year of sizable gains. Glass half empty: Stocks didn't ring in the new year on a particularly strong note. The three major indexes are all on track to end this holiday-shortened week down more than 1%.

Here's what to know:

• The Dow Jones Industrial Average, S&P 500 and Nasdaq Composite all recorded double-digit advances for a third straight year in 2025.
• But the U.S. market underperformed many of its international counterparts.
• Still, some big-name stocks had a milestone year. Alphabet and General Motors both recorded their biggest one-year gains in more than a decade.
• With stocks on a four-session losing streak, Wall Street is wondering whether the new year will put traders back in the buying mood.
• Despite the weak end to the year, market strategists are expecting more all-time highs in 2026.
• Follow live markets updates here.

Billionaire investor Warren Buffett has officially left his position as CEO of Berkshire Hathaway. In his six decades building a flailing textile mill into a $1 trillion behemoth, Buffett's Berkshire has delivered a whopping cumulative return of more than 5.5 million percent to shareholders.

In an interview with CNBC's Becky Quick, parts of which aired this morning, Buffett said Berkshire "has a better chance I think of being here 100 years from now than any company I can think of." Buffett, who is being succeeded by Greg Abel, will stay on as chair of the conglomerate.

But his departure as CEO leaves the question of who will run Berkshire's $300 billion equity portfolio. As CNBC's Yun Li notes, some investors aren't sold on Abel making investing decisions given his lack of a public track record as a stock picker.

In 2025, the artificial intelligence industry began remaking the American landscape — figuratively and literally.

Meta, OpenAI and Microsoft are among the tech companies planning hyperscale campuses around the country, turning farmland into compute factories that use massive amounts of electricity. As CNBC's MacKenzie Sigalos reports, these ventures are largely being funded by borrowing agreements, leading to concerns of an AI bubble.

The industry is also facing heat from politicians on both sides of the aisle, from Sen. Bernie Sanders to Florida Gov. Ron Desantis. As CNBC's Spencer Kimball explains, bipartisan concern about the data center boom could slow development — especially as politicians gear up for the 2026 midterm elections.

Stellantis is bringing back the TRX, its gas-powered Ram pickup truck equipped with a V-8 engine. The truck will be available later this year for roughly $100,000, Stellantis said yesterday.

As CNBC's Michael Wayland notes, Stellantis' announcement comes amid its turnaround plan and as the automaker faces looser federal emissions regulations. While its high price tag has put a lid on sales in the past, the TRX is seen as a "halo" for Ram: a high-end vehicle that drives brand attention, which can in turn boost purchases of other Ram models.

A class divide story has been playing out among U.S. airlines. As CNBC's Leslie Josephs reports, it's set to only intensify in 2026.

The biggest airlines have rushed to build out premium offerings for flyers willing to spend more. JetBlue is focusing on its more profitable routes and planning a domestic business class that's slated to launch in the middle of this year. Southwest started charging for checked bags for the first time in 2024. American is expanding its lounge system.

But on the other end of the spectrum, Spirit is battling to stay alive amid its second bankruptcy in less than a year. After a court blocked its acquisition of JetBlue, analysts now expect Spirit to attempt to merge with fellow budget air carrier Frontier Airlines.

Here are some stories we'd recommend make time for over the weekend:

• Will he stay or will he go? Powell is not saying whether he'll stay on Fed board when chair term ends
• Novo Nordisk is entering 2026 on the defense
• What the USPS' postmark policy means for your tax returns, ballots and bills
• This tech startup is bringing AI to the lunch line
• The biggest winners of 2025's space and defense boom
• Labor abuses and tariffs have clouded the champagne industry

CNBC's Sean Conlon, Sarah Min, Lee Ying Shan, Ari Levy, Michael Wayland, MacKenzie Sigalos, Alex Crippen, Yun Li and Leslie Josephs contributed to this report. Josephine Rozzelle edited this edition.