Major investor Warren Buffett donated $6 billion of Berkshire Hathaway stock to the Gates Foundation and four charities run by members of his family.

It is his largest annual donation since he began giving away his fortune nearly two decades ago.

Specifically, he donated 9.43 million shares to the Gates Foundation, 943,384 shares to the Susan Thompson Buffett Foundation, and 660,366 shares to each of three charities run respectively by his children, Howard, Susie, and Peter, the Howard G. Buffett Foundation, the Sherwood Foundation, and the NoVo Foundation.

Another $1.14 billion was given to family foundations last November.

With those donations, Buffett has given a total of more than $60 billion, CNN reports.

Buffett still owns 13.8% of Berkshire’s shares, based on reported shares outstanding.

His fortune (before the latest donation) reached $152 billion, making him the fifth richest man in the world, according to Forbes magazine’s analysis. After the donation, he ranks sixth.

Buffett, now 94, had begun donating his fortune in 2006. His will, which he renewed last year, stipulates that 99.5 percent of his estate left after his death will be given to a foundation overseen by his children. They will have to divide that amount over 10 years, in decisions made unanimously.