Charles Koch (net worth: $50.7 billion)

An elder brother of David Koch, Charles Koch is the chairman and chief executive officer of Koch Industries. Just like his brother, he also owns 42 percent of the company. Born in Wichita, Kansas, in 1935, Charles Koch is married and has two children. He supports a number of free market-oriented educational organizations, including the Institute for Humane Studies and the Mercatus Center at George Mason University.