Bill Gates just made his largest donation in 17 years

The Microsoft founder donated 64 million Microsoft shares–of 5% of his total shares–valued at $4.6 billion on June 6, Bloomberg reports. That donation is the largest by Gates in 17 years. In 1999 he gave away $16 billion worth of Microsoft shares and in 2000 he gave away $5.1 billion worth of shares. So who was the lucky recipient of the donation? The SEC filing that revealed the donation doesn’t say who or what organization received the shares, but Bloomberg speculates it could be the Bill & Melinda Gates Foundation, where Gates has given most of his donations to in the past.