Billionaire investor Warren Buffett's Berkshire Hathaway Inc. boosted its stake in WellPoint Inc. to 4.2 million shares in the second quarter, according to a regulatory filing.
The stake represents less than 1 percent of WellPoint's common stock. Even so, it's a fourfold increase from the first quarter, when Berkshire reported that it had amassed 979,000 shares.
Investors have speculated that Berkshire might want to acquire WellPoint outright. The Indianapolis company has a stock market value of $46 billion.
Berkshire said in last year's annual report that it needs to make big acquisitions to generate "truly satisfactory" earnings growth, and Buffett in May said that he is looking to spend $40 billion to $60 billion.Buffett also has said that Berkshire is looking for companies with consistent earnings, simple business plans, good return on equity and minimal debt.