The Gates Foundation recently sold 2.4 million shares of Berkshire Hathaway, which has attracted attention. The foundation now holds a 21% weight in BRK, worth $11 billion, but has been continuously reducing its position over the last quarter—from 30% to 25%.

What’s going on? There are two angles: first, Berkshire currently has $38 billion in cash, accounting for one-third of its market value, and Buffett obviously thinks the market is too expensive, as he can't even find bargains; second, the foundation needs to balance its investment portfolio, after all, having one stock account for a quarter of the weight is a bit ridiculous.

What's more interesting is that this wave of selling occurred at Berkshire's historical high, with a PE/B ratio reaching 1.6, exceeding the conventional trading range of the past decade (1.2-1.5). In other words, Gates and Buffett may both be hinting - this asset is a bit expensive now.