Microsoft co-founder Bill Gates sold 20 million company shares in late October, but thanks to market gains in the past three months, his portfolio was worth more than when he last sold stock, regulatory filings showed.
In the five days from October 27 to October 31, Gates sold the shares at prices ranging from $US45.92 to $US46.76 for a total of $US925 million, according to the US Securities and Exchange Commission (SEC).
At the end of his latest sales stretch, Gates owned 278 million shares worth about $US13.6 billion at Monday's closing price. When Gates sold stock in early August, his remaining portfolio of 298 million shares was then worth approximately $US12.9 billion.
The increase in the value of Gate's holdings - the sale of about 7 per cent of his portfolio notwithstanding - was due to the 12.7 per cent gain that Microsoft shares have posted since early August.
Gates, former CEO and chairman, has been selling about 80 million shares annually - usually 20 million each quarter - for more than a decade in a long-standing plan to fund the Bill & Melinda Gates Foundation. If Gates continues that pace, he will exhaust his Microsoft holdings in just under four years.
Gates ceded the title of largest Microsoft shareholder in April, when his holdings dipped under that of ex-CEO Steve Ballmer. Ballmer, whose last transaction recorded with the SEC was August 19, had 333 million shares on that date, worth $US16.3 billion at Monday's closing price if he has not sold any since.
Ballmer resigned from the Microsoft board of directors on August 19, severing his last official connection with the company. Ballmer said other commitments - including his new ownership of the Los Angeles Clippers professional basketball team - would occupy his time.
The Clippers played their first regular season game on October 30, a 93-90 win over the Oklahoma City Thunder.
Unlike Gates, Ballmer has repeatedly pledged to hold onto his Microsoft stock. "I promise to support and encourage boldness by management in my role as a shareholder in any way I can," Ballmer said in his August resignation letter to CEO Satya Nadella.