Warren Buffett piles another $1 billion into Occidental Petroleum boosting his bet on the energy stock to $7 billion in 11 days

• Warren Buffett spent another $1 billion on Occidental Petroleum stock in three days this week.
• Buffett's Berkshire Hathaway has now invested $7 billion in the energy company in 11 trading days.

Warren Buffett's Berkshire Hathaway plowed $1 billion into Occidental Petroleum over three days this week, meaning it's now bet a total of $7 billion on the energy stock in just 11 trading days.

The famed investor's conglomerate scooped up 18.1 million shares between March 14 and March 16, Securities and Exchange Commission filings show. Berkshire has now amassed 136 million shares since February 28, giving it a roughly 15% stake in the oil-and-gas company. Its position was worth $7.2 billion as of Wednesday's close.

Buffett backed up the truck after reading a transcript of Occidental's fourth-quarter earnings call, held on February 25.

"I read every word and said, 'This is exactly what I would be doing,'" the Berkshire CEO told CNBC. "We started buying on Monday, and we bought all we could."

Occidental stock has surged 71% this year, fueled by a historic spike in energy prices. The cost of oil and natural gas has soared thanks to a post-pandemic rebound in demand, and fears of supply disruptions due to Russia's invasion of Ukraine.

Buffett and his team have dealt with Occidental before. They provided $10 billion of financing to help the company acquire Anadarko Petroleum in 2019. In exchange, Berkshire received $10 billion worth of preferred shares in Occidental, along with warrants to buy 83.9 million common shares at an exercise price of $59.62.

If Occidental stock climbs above that level, Berkshire can exercise its warrants and sell the resulting shares at a profit. However, if it decides to keep those shares and retains its current holding, it would command a total of 220 million shares — a 22% stake worth over $13 billion at the exercise price.

Buffett is eager to deploy around $80 billion of Berkshire's almost $150 billion cash pile. However, he's been starved of attractive opportunities with stocks near record highs, and special-purpose acquisition vehicles (SPACs) and private-equity firms driving up the price of acquisitions. The investor may have finally found his long-awaited bargain in the form of Occidental stock.