Warren Buffett's retirement as CEO of Berkshire Hathaway has sparked questions about the future of its massive investment portfolio.

The conglomerate's first quarterly filing under new leader Greg Abel offers some answers.

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Berkshire Hathaway's 13-F filing with the SEC for the period ending March 31 reveals significant changes.

The company opened new positions in retailer Macy's and airline Delta Air Lines, while closing long-term holdings in Mastercard, Visa, Charter Communications, and Pool.

Magnificent Seven Moves

The most notable trades involve two Magnificent Seven stocks.

Berkshire completely exited its position in Amazon and purchased over 3.5 million shares of Alphabet, making Google's parent one of its largest holdings.

Buffett had long admired Amazon and publicly regretted not investing earlier. Berkshire only started buying Alphabet in the third quarter of 2025, making it a relatively new addition.

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Abel clearly favors Alphabet over Amazon now. The shift reflects a strategic bet on Google's parent company.

Comparing Amazon and Alphabet

Both companies are Magnificent Seven members, a group that includes Nvidia, Apple, Microsoft, Tesla, Meta Platforms, Amazon, and Alphabet.

These seven stocks represent over a third of the S&P 500 and gained 875% from 2016 through 2025.

Both are major players in cloud computing and artificial intelligence.

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Amazon Web Services leads the cloud infrastructure market with 28% global share, followed by Microsoft Azure at 21% and Google Cloud at 14%.

Growth rates differ significantly. AWS generated $37.5 billion in Q1 revenue, up 28.5% year over year.

Google Cloud brought in $20.1 billion, up 63%.

Alphabet's faster growth in cloud and its dominant position in digital advertising may explain Abel's preference.

The move signals a potential shift in Berkshire's investment philosophy under new leadership.

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The filing, made on May 20, 2026, covers the period ending March 31. It is the first 13-F since Buffett stepped down as CEO.