Google co-founder Sergey Brin has donated $600 million worth of shares in Alphabet, Inc., Google’s parent company, to an unnamed source, Bloomberg reports. 

Brin’s donation appeared in a Securities and Exchange Commission filing earlier this week, which shows 5.2 million shares were evenly split between newly converted Class A stock and Class C stock. Brin’s net worth is now $100.7 billion, according to the Bloomberg Billionaires Index.  

Brin has sold more than $10 billion worth of shares since Alphabet’s initial public offering in 2004, according to data compiled by Bloomberg. 

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