Thomas Peterffy, founder and chairman of Interactive Brokers, is ranked No. 23 on the Forbes 2026 World’s Billionaires list with a net worth of $82.9 billion. He arrived in the United States from Hungary in 1965 speaking no English.
Thomas Peterffy was born on September 30, 1944, in Budapest, Hungary, in a hospital basement during an air raid. His father emigrated to the United States after the failure of the Hungarian Revolution in 1956, and Peterffy left his engineering studies in Hungary to join him in New York in 1965. His father gave him $100 and told him to make something of himself.
Net Worth and Rank
- Forbes 2026 list: No. 23, with $82.9 billion
- Later estimate: Wikipedia cites an estimate of $109 billion as of November 2025
From Draftsman to Trader
Peterffy enrolled at New York University’s engineering school but dropped out to work as an architectural draftsman on highway projects. He volunteered to program a newly bought computer, and became a programmer of financial modelling software.
- 1977: he bought a seat on the American Stock Exchange to trade equity options
- 1978: he formed the trading firm T.P. & Co., the origin of Interactive Brokers
- Early 1980s: he caused a stir by bringing handheld computers onto the trading floor
Interactive Brokers
Peterffy pushed throughout his career to replace manual processes with automated ones, and helped to develop the first electronic trading platform for securities. He is the founder, chairman and largest shareholder of Interactive Brokers, an online discount brokerage. He stepped down as chief executive in 2019.
Politics
Peterffy is a Republican donor. He gave over $60,000 to the Republican National Committee in 2011 and $100,000 to a pro-Trump political group in 2016, and supported Donald Trump in the 2024 election.
Why It Matters
Interactive Brokers is a large online discount brokerage, and Peterffy’s stake in it is the main source of his fortune.
Net worth figures change daily with share prices. Rankings here follow the Forbes 2026 World’s Billionaires list, with wealth measured on March 1, 2026.
Image: The operations room of Interactive Brokers, the brokerage Thomas Peterffy founded (file photo, 2014; he is not pictured). Photo: Ɱ / Wikimedia Commons (CC BY-SA 4.0)
