Forbes reports privately-held game developer Valve is estimated to be worth more than $3 billion. Valve co-founder Gabe Newell owns more than 50 percent of the company, giving him an estimated net worth of $1.5 billion. The magazine puts him 854th on the list of 1,226 global dollar billionaires.
Privately-held Valve Corporation is tight-lipped about revenues, and Newell doesn
