OMAHA, Neb. — Warren Buffett’s Berkshire Hathaway bought more than $500 million worth of Occidental Petroleum shares over the past week as it continued to invest heavily in oil producers this year.

Shares of Occidental gained more than 2% to trade at $57.11 today after Berkshire disclosed owning 16.3% of the company’s common stock. The Omaha, Nebraska-based conglomerate the billionaire leads disclosed its latest purchases in a filing with the Securities and Exchange Commission Wednesday.

Berkshire purchased nearly 9.6 million Occidental shares in several blocks on Friday and Wednesday. After these latest purchases, Berkshire now owns 152.7 million shares in the Houston-based oil producer, but Berkshire also holds 100,000 preferred shares in the company and warrants to buy another 83.9 million Occidental shares for $59.62 apiece that it picked up in 2019 when it helped finance Occidental’s purchase of Anadarko.

In addition to its Occidental investment, Berkshire picked up more than $20 billion worth of Chevron shares earlier this year to make it one of the conglomerate’s five biggest investments alongside its massive Apple stake and sizeable investments in Bank of American, American Express and Coca-Cola stock.

Berkshire invested more than $51 billion in stocks during the first quarter of this year as the market fell, Berkshire won’t reveal all its second-quarter purchases until later this summer.

In addition to his stock purchases, Buffett sealed a deal earlier this year to buy the Alleghany insurance conglomerate for $11.6 billion.

Besides investments, Berkshire Hathaway owns more than 90 companies outright, including BNSF railroad, several large utilities, Geico and a number of other insurers and an eclectic assortment of manufacturing and retail firms that includes Precision Castparts, Fruit of the Loom and Dairy Queen.