Bill Gates made his largest single gift since the turn of the century, giving away Microsoft shares that accounted for 5 per cent of his fortune, the world's biggest.
The billionaire donated 64 million of the software maker's shares to the Bill & Melinda Gates Foundation on June 6, according to Securities and Exchange Commission filings released Monday.
The shares were valued at $4.6 billion (NZ$6.3b) at the time.
It's the largest gift of Microsoft shares that Gates, 61, has made since 2000. He gave away $16 billion worth of the stock in 1999 and $5.1 billion a year later, according to calculations by Bloomberg.
"It's a change in how he distributes that asset," said Ben Silverman, research director at InsiderScore, noting that Gates has been reducing his stake methodically for years through share sales to fund his foundation.