Berkshire Hathaway added to its Chevron bet significantly during the first quarter, making the energy stock the conglomerate’s fourth biggest equity holding.

The “Oracle of Omaha’s” Chevron investment was worth $25.9 billion at the end of March, the company’s first-quarter filing Saturday showed, a big jump from its value of $4.5 billion at the end of 2021.

Shares of Chevron have rallied more than 30% this year on the back of surging oil prices, but Berkshire’s position has increased fivefold reflecting Buffett’s buying.

Energy has been a standout winner this year with the S&P 500 energy sector up 35% compared to the broader benchmark’s 13% loss year to date.

Many oil and gas companies are also good income generators, offering attractive dividends. The energy sector yields 4.7%, compared to S&P 500′s 1.5% dividend yield. Chevron pays a 3.6% dividend.

Buffett first bought Chevron in the third quarter of 2020.

Chevron is not the only energy stock Buffett likes. Last month, the investor bought $7 billion worth of Occidental Petroleum‘s common shares in additional investments.

“Together with the $10 billion in OXY preferred, Berkshire’s bet on the oil sector is now over $40 billion,” said James Shanahan, a Berkshire analyst at Edward Jones.

Berkshire’s biggest holding was still Apple, worth $159 billion at the end of the first quarter. Bank of America and American Express were the two other big holdings, worth $42.6 billion and $28.4 billion, respectively.

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