In the middle of the first quarter, Warren Buffett's company, Berkshire Hathaway (BRK.A 0.64%) (BRK.B 0.54%), had to disclose it had made a large bet on Occidental Petroleum (OXY 0.09%). That's because the giant Buffett conglomerate had taken a stake that exceeded 10% of Occidental's stock, prompting a disclosure.

That purchase in Occidental, which seemed like a leveraged bet on higher oil prices, appeared to indicate Buffett was bullish on oil prices following Russia's invasion of Ukraine. But it also could have been for factors specific to Occidental.

It turns out that Buffett was making an even more massive bet on oil prices at the time, the full extent of which he didn't have to disclose until now.

Chevron is now a top-three position for Berkshire, ahead of AmEx and Coke

While Berkshire had to disclose its position in Occidental, it didn't have to do so for a huge increase in its position in Chevron (CVX 0.75%). Because Chevron is a much larger overall company, Berkshire was able to increase its share of the company from 2% at the end of the fourth quarter of 2021 to 8.9% by the end of the first quarter of 2022.

Thanks to rising oil prices and Chevron's rising price, the stake has now overtaken famous longtime Buffett holdings American Express and Coca-Cola in terms of size. At today's prices, Chevron now makes up 7.7% of Berkshire's $353 billion portfolio, its third-largest position, behind Apple in first and Bank of America.

When combined with Occidental's 2.1% allocation, Buffett has now bet 9.8% of Berkshire's public equity portfolio on these two oil and gas producers. That's more than double the relative allocation to energy in the S&P 500, at just 3.86%.

Smiling Warren Buffett.

Image source: Getty Images.

Ukraine and the "casino" of Wall Street enabled the purchase

Buffett has been somewhat bullish on the oil and gas sector over the past two years, purchasing its initial Chevron stake in late 2020 and acquiring the natural gas assets from Dominion Energy (D 0.52%) in mid-2020. These followed a preferred-stock investment in Occidental in 2019, which helped fund the company's acquisition of Anadarko.

Buffett probably liked the prices at which he could buy these assets. Investors focused on environmental, social, and governance (ESG) issues eschew traditional energy stocks, and exploration and production companies have limited their investments over the past decade of low energy prices. So the traditional energy sector had likely become the type of value investment Buffett seeks.

Given the aggressive pace of the purchases, it appears Russia's invasion of Ukraine stimulated Buffett's decision to act big and act quickly. Berkshire normally can't buy that much stock that quickly even if it wanted to, because it buys stock in such large size.

However, Buffett lamented the more "casino-like" nature of modern markets that enabled Berkshire to buy such a big stake so quickly. Since a large chunk of Occidental is locked up in index funds, Buffett was even more surprised he could buy so much of the company in such a short time. While it was good for Berkshire, Buffett lamented the fact that the purchase was even possible. Speaking to CNBC at Berkshire's annual shareholders meeting on Saturday, he said:

That's not investment. You're not buying from [investors]. I find it just incredible. You couldn't do that with Berkshire. ... Overwhelmingly, large companies in America, they became poker chips. ... That enabled us, in a two-week period, to buy 14% of a business that's been around for decades. ... Imagine trying to [buy] 14% of the farms in this country, 14% of the apartment houses, 14% of the auto dealerships, or just anything, when already 40% were locked up some other place. It defies anything Charlie and I have seen, and we've seen a lot.

Is the oil trading over, or just getting started?

Some might think Berkshire may be buying oil stocks near the top of the energy market. After all, oil prices have doubled since the beginning of 2021, and Buffett was buying on the way up. Moreover, there are now widespread fears about a recession later this year or next year, which could hurt oil demand. The U.S. rig count is also rising, which should bring supply on line later this year, and the government is even releasing 1 million barrels of oil per day for the next six months from the Strategic Petroleum Reserve.

On the other hand, Europe is now contemplating a quicker-than-expected embargo of Russian oil due to its atrocities in Ukraine. Moreover, the COVID-19 lockdowns in China could lift in the near future, at about the same time as the summer highway-travel season in the U.S. So there is also a case to be made that oil could be in for further gains (or at least stability at these high levels) for the foreseeable future.

In any case, Buffett tends to take a longer-term view of these things. More likely, he sees a structural supply shortfall over the next decade, and sees the high dividends from oil companies as durable. As a justification for his initial preferred-stock financing of Occidental back in 2019, he admitted the financing was a bet on higher oil prices over the long term. Given an even more favorable setup today, that view likely hasn't changed.

Individual investors should make their own decisions about their allocation to traditional energy. However, the transition to clean energy won't happen overnight. As long as the world uses fossil fuels, there will be a need for traditional energy companies. Those without any exposure should take note of Buffett's recent bet.