Warren Buffett is going on his biggest shopping spree since the crash

After years of complaining that high valuations thwarted its stock-buying efforts, Warren Buffett’s Berkshire Hathaway is back to sucking up other companies’ stocks.

The conglomerate made about $41 billion in net purchases in the first quarter, including an increase in its Chevron stake, which catapulted investment into Berkshire’s four largest common stocks. Mr. Buffett also announced that the company now holds an expanded 9.5 percent stake in Activision Blizzard — an arbitrage bet on the video game maker, which is in the process of being acquired by Microsoft.

Berkshire has not been such a significant net buyer of common stock in the data in a quarter since 2008. Mr. Buffett’s bustle over the past few months prompted a series of questions from shareholders in 2019 at his first in-person annual meeting since Saturday.

The meeting, held in Mr. Buffett’s hometown of Omaha, Nebraska, lasted for hours as the CEO and his business partner, Charlie Munger, answered questions about markets, nuclear weapons, and even Bitcoin.

Mr. Buffett, 91, and his deputies have struggled in recent years to find ways to invest Berkshire’s money in higher-yielding assets, in part due to stiff competition from buyers, including private equity firms, as well as high valuations is.

But Berkshire executives were active again for the first three months of the year, buying more shares of Occidental Petroleum and inching a deal to buy Alleghany for $11.6 billion in cash.

Berkshire’s massive common stock stake in Occidental was one of the largest disclosed purchases in the first quarter, adding to the $10 billion that Berkshire had previously invested in the oil producer. Mr. Buffett noted that the investment came quickly after spending a weekend reading a presentation by CEO Vicki Hollub.

“What Vicki Hollub said made nothing but sense, and I decided it was a good place to put Berkshire’s money,” Mr. Buffett said.

“And two weeks later we had 14 percent of the company.”

Berkshire’s sizeable investment in Chevron during the quarter, combined with its $10 billion investment in Occidental preferred stock, adds up to a $40 billion bet on the oil sector, said Edward Jones analyst Jim Shanahan.

The purchases helped deplete Berkshire’s cash pile, which ended the first quarter at $106 billion, its lowest since the third quarter of 2018. The hoard had been near record levels over the past few quarters.

As Berkshire revved up its stock-buying engine, the company slowed its share repurchases during the quarter with just $3.2 billion in share repurchases in 2021.

Mr. Buffett had increasingly relied on buybacks as a way to stake money in a competitive business environment. Berkshire’s Class A shares were more expensive during the period, with a gain of more than 17 percent in the first quarter.

The conglomerate’s first-quarter profit rose just 0.3 percent year-on-year to $7.04 billion.