Gabe Newell net worth: Gabe Newell is the co-founder of the video game company Valve Corporation who has a net worth of $1.5 billion. Gabe Newell earned this net worth from many years as a Microsoft executive and as the CEO of the video game company Valve Corporation which produces wildly popular games like Half-Life and Counter-Strike. Valve Corporation is valued at over $2 billion. Before founding Valve, Gabe Newell spent 13 years working at Microsoft where he became a "Microsoft Millionaire". While at Microsoft, Newell worked on three different version of Windows. In 1996, Gabe Newell and a Microsoft co-worker named Mike Harrington left to form Valve with their own money. Valve would go on to produce a string of wildly successful video games including Half-Life, Counter-Strike, Day of Defeat, Portal and many more.