T homas Peterffy is a Hungarian-born American billionaire who is a revolutionary pioneer in the field of digital and automated securities trading. He fled communist Hungary in 1965 and arrived in the United States as a refugee with no money and unable to speak English. He began his career as an architectural draftsman and then taught himself computer programming. In the late 1970s, he bought a seat on the American Stock Exchange and began to apply his programming skills to the world of trading, developing some of the first automated algorithmic trading models and creating the first handheld computers for use on the trading floor.

In 1993, he founded the electronic brokerage firm Interactive Brokers. He built the company into one of the largest and most successful electronic brokers in the world, renowned for its low-cost, high-speed, and technologically advanced trading platform that caters to sophisticated and active traders. He is widely considered one of the fathers of modern electronic trading, having transformed the industry from an open-outcry system to a digital marketplace. Now a resident of Florida, he has retired as CEO but remains the chairman of the company he founded, and he is a major donor to the Republican party.