Just caught something interesting about the recent 13F filing season. With Warren Buffett officially stepping back at the end of last year, Greg Abel is now running a $318 billion investment portfolio at Berkshire Hathaway — and the concentration is pretty striking.

I was looking at the numbers and nearly 61% of their invested assets are locked into just five positions. Apple leads at 19.5%, followed by American Express at 15.3%, Coca-Cola at 10.1%, Bank of America at 8.2%, and Chevron at 7.6%. That's a pretty concentrated bet for a portfolio of that size.

What caught my attention though is how differently these holdings might be treated going forward. The Coca-Cola and American Express positions are what Buffett himself called "indefinite" holdings — and for good reason. These aren't recent purchases. Coca-Cola's been in the portfolio since 1988, Amex since 1991. The yield on cost is absolutely insane: 63% for Coca-Cola and 39% for Amex based on their original cost basis. You don't sell positions generating returns like that.

But here's where it gets interesting. While Warren Buffett built positions in Apple and Bank of America that worked out brilliantly, the valuation math has changed dramatically. Apple's P/E ratio has nearly tripled since Buffett started buying in 2016 — it's sitting at 34x earnings now, which is expensive by any measure. Bank of America is even more telling: when Buffett opened that preferred position back in 2011, the stock was trading at a 62% discount to book value. Today it's trading at a 31% premium. That's a massive swing.

Given that Warren Buffett and Abel both share an obsession with value, I wouldn't be shocked if we see some meaningful reductions in these two positions. The principles haven't changed — it's just that the valuations don't support the same conviction anymore.

Chevron's situation is different though. Abel ran MidAmerican Energy before it became Berkshire Hathaway Energy, so he understands energy dynamics deeply. Chevron's integrated model — drilling, pipelines, refineries, chemicals — provides natural hedges. That could actually become a more foundational holding under new leadership.

The transition is worth watching. New management at scale always brings subtle shifts in strategy, even when the core philosophy stays intact.