So Greg Abel officially took over Berkshire Hathaway's massive portfolio at the start of this year, and the latest 13F filing just dropped some interesting details about what Warren Buffett left him to manage. We're talking about a $318 billion investment portfolio, which is... yeah, basically a lot to inherit.

What caught my attention is how concentrated this thing actually is. According to the February filing, just five stocks make up 61% of everything Berkshire has invested. 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 rounding it out at 7.6%. It's a pretty tight core holding situation.

Now here's the thing about Coca-Cola and Amex - these aren't going anywhere. Warren Buffett specifically called them out as "indefinite" holdings back in his 2023 shareholder letter, and for good reason. Berkshire's been sitting on Coca-Cola since 1988 and American Express since 1991. The yield on cost is absolutely ridiculous at this point - we're talking 63% annual yield for Coke and 39% for Amex based on their original cost bases. Why would Abel even think about touching those?

But here's where it gets interesting. Both Apple and Bank of America might tell a different story. Apple's P/E has basically tripled since Warren first started buying it back in 2016. The company's got an incredible buyback program and loyal customers, but at a P/E of 34, it's not exactly screaming "bargain" anymore. Bank of America is similar - back in 2011 when Berkshire got in, BofA was trading at a 62% discount to book value. Now it's trading at a 31% premium. That's a pretty significant shift in valuation.

Given that Abel clearly cares about value - that's kind of his thing - don't be shocked if he starts trimming those positions down. He's got a different investment philosophy, and overpaying for quality is probably not where his head's at.

Chevron's interesting because Abel actually spent years running MidAmerican Energy before it became Berkshire Hathaway Energy. He understands the energy space inside and out, so that holding might actually stick around and potentially even grow. The company's integrated model - pipelines, refineries, chemical plants - gives it good protection when oil prices dip.

The core principles that built Berkshire won't change under Abel, but the portfolio composition probably will. Worth keeping an eye on how things shake out over the next couple quarters.