Warren Buffett's Berkshire Hathaway plowed more than $5 billion into 4 pharma stocks last quarter. He's been teasing a bet on the sector for more than 20 years

• Warren Buffett's Berkshire Hathaway bought more than $5 billion worth of AbbVie, Bristol Myers Squibb, Merck, and Pfizer stock last quarter.
• The billionaire investor has been teasing a wager of that kind for more than 20 years.
• "If we could buy a group of leading pharmaceutical companies at a below-market multiple, I think we'd do it in a second," Buffett said at Berkshire's annual meeting in 1999.
• Buffett also touted a "basket approach" to the pharmaceutical industry as a way to deploy "quite a bit of money" in 2002.
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Warren Buffett's Berkshire Hathaway plowed more than $5 billion in total into AbbVie, Bristol Myers Squibb, Merck, and Pfizer in the third quarter. Close followers of the company won't be surprised, as Buffett has been mulling a bet on the pharmaceutical sector for more than 20 years.

"You could've just bought the whole industry and done very well," the famed investor said at Berkshire's annual shareholder meeting in 1997. He was referring to the downturn in drug stocks in the early 1990s, sparked by President Bill Clinton's proposed healthcare reforms. "We didn't do it. It was a mistake."

"We stupidly blew that one," Charlie Munger, Berkshire's vice chairman and Buffett's longtime business partner, said at the 1998 meeting.

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Buffett emphasized at the 1999 meeting that he lacks the specialist knowledge to pick a winner in the sector, but suggested an investment in several drugmakers could pay off handsomely.

"If we could buy a group of leading pharmaceutical companies at a below-market multiple, I think we'd do it in a second," he said.

The Berkshire chief — who has name-checked Bristol Myers Squibb, Merck, and Pfizer during annual meetings over the years — summed up his view in 2002.

"It's hard to evaluate the individual companies," he said during that year's shareholder gathering. "But that's no reason not to have a basket approach to the industry."

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"At some valuation level, it would be something we would think very hard about," Buffett continued. "And it's something where we could put quite a bit of money if it happened, which is another plus to us."

The size of Berkshire's pharma investments — less than $2 billion in each of AbbVie, BMS, and Merck, and under $150 million in Pfizer — suggests one of Buffett's portfolio managers, Ted Weschler and Todd Combs, was likely behind them.

However, the decision to buy four stocks instead of one might well be a product of Buffett's thinking over the years.