Berkshire Hathaway today disclosed that at the end of the fourth quarter of last year it held 57.35 million shares of Apple stock. That’s almost four times as many shares as it had at the end of the third quarter (15.22 million).

Berkshire Hathaway, led by legendary value investor Warren Buffett, also owns stakes in other major public companies, including American Express, Coca-Cola, Bank of New York-Mellon, Charter Communications, Delta, GE, General Motors, Goldman Sachs, IBM, Kraft Heinz, Moody’s, Phillips 66, Sirius, U.S. Bancorp, and Wells Fargo. But it only revealed some ownership of Apple stock at the end of the first quarter of 2016.

Shortly after that, Apple started stumbling — iPhone revenue and unit sales both decreased, and that pattern continued for the two subsequent quarters. Apple achieved record sales and saw iPhone growth return in the most recent quarter, but it was a long 14-week quarter.

For much of 2016, people asked if Apple’s days as a growth stock were effectively behind it, leading it to be a value stock — the sort of thing that Buffett is known to like.

To be clear, Berkshire is not Apple’s biggest shareholder. BlackRock and Vanguard are among the firms that hold larger stakes in Apple.

Today Apple stock closed at an all-time high of $135.02.