Warren Buffett thanked Apple CEO Tim Cook at the Berkshire Hathaway annual shareholder meeting Saturday for making the Oracle of Omaha and his investors a lot of money over the past few years. But is Berkshire's investment in Apple starting to sour?

Apple shares are down 20.6% this year, making them the second-worst performer in the Magnificent Seven. Only Elon Musk's Tesla has had a rougher 2025, with Tesla shares tumbling 30.6%.

To be sure, Buffett, who announced at the shareholder meeting Saturday that he will step down as Berkshire CEO at the end of this year, is still a big fan of Apple. Berkshire Hathaway owns 300 million shares of the company, an investment worth a little more than $60 billion. Apple is the largest stockholding in Berkshire's portfolio, making up nearly a quarter of the equity holdings.

But Berkshire slashed its stake in Apple last year. It began 2024 with more than 905 million Apple shares.

The Apple investment hasn't been the big success this year that it has been in prior years. What's more, Apple has fallen nearly 5% in just the past five days, after the company said in its earnings report last week that sales in China were below forecasts. That raised fears about how the trade war between the U.S. and China could have a bigger impact on Apple going forward.

As a result of Apple's pullback, Microsoft has once again pulled ahead of Apple in terms of market cap. Microsoft is worth nearly $3.3 trillion versus a market value of $3 trillion for Apple. Microsoft shares are up 3.5% this year, making them the best performer in the Magnificent Seven.

It isn't clear if Berkshire will look to sell any more Apple shares any time soon. It left its stake at 300 million shares in the fourth quarter of 2024 following the big sales earlier last year. Berkshire will reveal its holdings for the first quarter in a regulatory filing on May 15.

Going forward, Buffett likely will still have some say over what's in Berkshire's portfolio for the foreseeable future since he will remain the company's chairman.

But Buffett's appointed successor as CEO, Greg Abel, is unlikely to make any major changes once he takes the reins of the company.

"Abel has previously expressed to shareholders that the company's investment philosophy will not change under his leadership," noted CFRA analyst Cathy Seifert in a report Monday.

That likely means that Apple will continue to be a core holding of the Berkshire portfolio for the foreseeable future.

It's also worth noting that Apple's woes aren't having a major impact on Berkshire's performance this year. Berkshire shares, despite a 5% pullback Monday on the news of Buffett's impending retirement as CEO, are still up 13% this year while the broader market has slid.

In fact, many other top Berkshire investments, such as American Express, Bank of America and Chevron, are down in 2025. Longtime Buffett favorite Coca-Cola is the notable exception. It's up 15% this year, making it the top stock in the Dow Jones Industrial Average.

"Buffett leaves a company that is less reliant on his investing capabilities, with an array of leading businesses with strong cash flows, " said UBS analyst Brian Meredith in a report Monday.

In other words, the continued future success of Berkshire will have more to do with how operating units like Geico and other Berkshire-owned insurance businesses as well as the company's many other industrial, energy, financial and consumer subsidiaries are doing than the performance of the stocks in Berkshire's portfolio.