Warren AI Thinks It’s Found Buffett’s Mystery $5 Billion Bet…But the Real Story Was Even Smarter

When We asked AI to identify Warren Buffett’s mystery stock, it confidently pointed to Caterpillar (NYSE:CAT)—citing attractive metrics like a 16.4× P/E, 55.4 % ROE, and a 5.5 % free cash flow yield—attributes it deemed “closest fit to classic Warren Buffett/Berkshire Hathaway style.

Sounds compelling. But that’s just the start of a story that Buffett-watchers know all too well: expect the unexpected.

Enter the real reveal: A trio, not one

In its August 14 Form 13‑F filing, Berkshire Hathaway, led by Warren Buffett, unveiled not a single “mystery stock” but three—all strategically aligned with housing, manufacturing, and steel:

• Lennar – ~$799 million investment
• D.R. Horton – ~$191 million
• Nucor – ~$856 million

These names had been kept under wraps in the Q1 filing using SEC confidential treatment, only to surface now in Q2’s amended report.

What does this tell us?

Buffett’s move wasn’t a curveball—it was classic Berkshire: diversified bets in foundational industries rather than media headlines. It underscores a renewed confidence in post-pandemic housing demand and American manufacturing resilience.

As Barron’s noted, these investments—though relatively modest for Berkshire’s nearly $300 billion equity portfolio—did signal an industrial tilt by their pattern and timing.

Meanwhile, Investopedia highlighted the biggest piece of the puzzle: that $1.6 billion stake in UnitedHealth Group (UNH), alongside new positions in Allegion, D.R. Horton, Lamar Advertising, and Nucor—and trimming exposures in Apple and Bank of America.

In essence: AI speculated spectacularly. But Berkshire delivered with strategic breadth.