Donation is biggest in billionaire's plan to give away fortune Bill & Melinda Gates Foundation receives 80% of shares gift Warren Buffett is donating roughly $3.6bn of Berkshire Hathaway stock to five charities including the Bill & Melinda Gates Foundation, the biggest contribution in Buffett's plan to give away his fortune. Berkshire said Buffett's 14th annual donation comprises about 16.81m class B shares of Berkshire.