Warren Buffett remains the fourth-richest person in the world, but his pockets are now significantly lighter. As part of his annual giving spree, the billionaire announced Monday he would donate $3.17 billion in Berkshire Hathaway stock to five charities. The Bill and Melinda Gates Foundation will receive the largest share at $2.42 billion, reports Reuters, with the remainder split between family charities: the Susan Thompson Buffett Foundation, the Howard G. Buffett Foundation, the Sherwood Foundation, and the NoVo Foundation. Since 2006, Buffett has given $27.5 billion to the five groups, reports CNNMoney. (Buffett has vowed to give away 99% of his fortune.)