Bill Gates, 61, donated 64 million in Microsoft shares, worth $4.6 billion, to the Bill and Melinda Gates Foundation June 6, according to an Aug. 14 U.S. Securities and Exchange Commission filing.
The shares accounted for roughly 5 percent of his personal fortune, Bloomberg reports.
The donation comprised approximately 38 percent of Mr. Gates' holdings in the technology company. It also represents the largest gift Mr. Gates has made to the foundation since 2000. He previously donated $16 billion worth of stock in 1999 and $5.1 billion of shares in 2000, Bloomberg calculated.
Mr. Gates also unveiled the foundation's new campaign to combat malaria in a blog post Aug. 15. Under the "Mosquito Wars" initiative, the foundation will donate a mosquito net for every person who reads his latest blog post and takes the subsequent quiz. Each mosquito net will go to families in the Inhambane region of Mozambique, Africa.
To learn more about the Bill and Melinda Gates Foundation's efforts to combat malaria, click here.