Facebook CEO Mark Zuckerberg is donating half a billion dollars in Facebook stock to a Silicon Valley charity in his largest donation to date. As reported by The Associated Press, the recipient is the Silicon Valley Community Foundation, which will decide, along with Zuckerberg, exactly how to dish out the cash. It has been said that the money will be used to focus on health and education issues.

The donation of 18 million shares had a closing price of $498.8 million on Tuesday, making it roughly five times the size of Zuckerberg’s 2010 donation to Newark, New Jersey’s public school system. Later the same year, Zuckerberg signed the Giving Pledge, an initiative engineered by Bill Gates asking the world’s richest to give away the majority of their fortunes.