UnitedHealth Group Inc. (UnitedHealth (UNH)) shares are sliding in Monday's premarket after Berkshire Hathaway revealed it dumped its entire stake in the healthcare giant. The move comes as UnitedHealth doubles down on artificial intelligence, tracking how often employees use tools like ChatGPT and investing billions to transform its operations.

According to Berkshire's latest 13F filing, which covers holdings as of March 31, the conglomerate sold off about 5 million shares of UnitedHealth — a position it only started building in the second quarter of 2025. That means Berkshire held the stock for less than a year, a relatively short stint for the famously patient investor.

The divestment is part of a broader portfolio overhaul under Greg Abel, who took over as Berkshire's CEO on January 1 after Warren Buffett stepped back. Abel is putting his own stamp on the company's investments, and UnitedHealth didn't make the cut.

It's worth noting that the stake was relatively small for Berkshire — about 5 million shares — and the filing also showed that investor Michael Burry had purchased call options on 350,000 UnitedHealth shares, adding a layer of intrigue to the stock's recent moves.

UnitedHealth Tracks Employee AI Usage as Automation Push Accelerates

Separately, UnitedHealth is reportedly monitoring how often some employees use artificial intelligence tools, signaling a major push to embed AI into its daily operations. According to Bloomberg, which cited people familiar with the matter, the company is tracking whether workers in its Optum services division use platforms like ChatGPT and Microsoft's Copilot at least once a day.

A UnitedHealth spokesperson told Bloomberg that the company is "investing heavily in AI to reshape how we operate and organize work in the future." The spokesperson added that UnitedHealth has already rolled out more than 1,000 AI use cases and is expanding AI-related training for both employees and external customers.

An internal training document reviewed by Bloomberg described an engagement dashboard that monitors AI adoption, tracks employee training progress, and flags areas where usage is lagging. The document also highlighted some impressive numbers: AI applications helped avoid more than 15 million calls, processed hundreds of millions of claims, and generated over 150 million lines of code.

The training program, internally called "AI Dojo," has received positive feedback from employees who completed it. It's all part of a broader effort to make AI a core part of how UnitedHealth operates.

AI Push Tied to Broader Recovery Strategy

Last year, UnitedHealth began testing a platform called Optum Real, designed to speed up medical claims processing. And in April, company executives said UnitedHealth plans to invest about $1.5 billion in AI this year, with expectations of generating at least a two-to-one return on those investments — with benefits showing up within the first year.

The AI push comes alongside strong financial results. UnitedHealth reported better-than-expected first-quarter earnings, with adjusted earnings of $7.23 per share, beating the consensus estimate of $6.58. Revenue rose 2% year over year to $111.721 billion, also topping expectations of $109.58 billion. The company raised its fiscal 2026 earnings guidance above analyst estimates.

Despite the positive earnings, UnitedHealth shares were down 3.05% in premarket trading Monday at $381.84. Over the past month, the stock has gained about 18%, compared to a 4.3% rise in the S&P 500, and is up roughly 16% year-to-date versus the index's 7.8% gain.

So while Berkshire's exit might sting in the short term, UnitedHealth's AI ambitions and solid fundamentals suggest the company is betting big on technology to drive future growth.