Thomas Peterffy

Thomas Peterffy (born September 30, 1944) is a Hungarian-born American billionaire businessman. He is the founder, chairman and the largest shareholder of Interactive Brokers. As of November 2025, his estimated net worth is US$57.3 billion, making him the 27th richest person in the world. Peterffy worked as an architectural draftsman after emigrating to the United States, and later became a computer programmer.

In 1977, he purchased a seat on the American Stock Exchange and played a role in developing the first electronic trading platform for securities. Peterffy is a donor to the Republican Party and conservative causes.