Microsoft’s (MSFT) Bill Gates already is the second richest person in the world and the richest in the United States, amassing a $79.2 billion fortune, according to Forbes’ latest statistics of such things.

What’s another $882 million among friends? Gates, benefitting from a bounce in the value of Microsoft’s shares, which have run up 10 percent in the last three months and 36 percent in the past year, sold 20 million shares in four separate transactions July 28-31 at share prices topping out at $44.54, to pocket a cool $882 million in cash.

Gates has been selling about 20 million shares a quarter, or 80 million a year, for the past 10 years or so to fund his philanthropic foundation, in keeping with his pledge to give away much of his wealth. At this rate, he will deplete his holdings in the next four years.

The stock sale, documented in Microsoft’s SEC filings, pared Gates’ Microsoft holdings to 298 million shares worth $12.8 billion, the first time the founder’s holdings have slid under the 300 million shares mark. This past April, Gates relinquished his position as the company’s top shareholder when his portfolio ducked under the 333 million shares owned by former chief executive Steve Ballmer.

Ballmer’s shares currently are valued at $14.3 billion based on the $43.08 Aug. 5 closing price.

Gates, who’s been the richest man in the world for 15 out of the last 20 years, according to Forbes, recently agreed to help launch a new philanthropic education program at Beijing Normal University. The program seeks to raise $16.1 million a year from wealthy people in China and the United States.

Last February, Gates stepped down as Microsoft chairman and signed on as a technology adviser to new chief executive Satya Nadella. By keeping mum during the company’s recent overhaul, Gates undoubtedly helped to solidify Nadella’s position as the company’s leader.