Brian Acton

Computer engineer Brian Acton cofounded messaging app WhatsApp with Jan Koum in 2007; the two had met while working at Yahoo. The pair sold WhatsApp to Facebook for $22 billion in cash and stock in 2014. Acton received about $3 billion for his stake in WhatsApp. WhatsApp is now one of the biggest mobile messaging apps with 1.3 billion monthly active users, mostly outside of the United States. Brian Acton donated Facebook shares worth nearly $290 million to the Silicon Valley Community Foundation following Facebook's acquisition of WhatsApp.