.jpg?width=512)
Thomas Peterffy arrived in the United States from Hungary with little money and no English, then used programming and market-making to build the business that became Interactive Brokers. [1][2]
From Hungary to Wall Street
Peterffy emigrated from Hungary to the United States in 1965 at age twenty-one. Forbes describes him arriving with almost no money and unable to speak English, then finding work as an architectural draftsman before teaching himself computer programming at an engineering firm. [2][3]
Programming led Peterffy into finance, where he built trading models and saved enough money to buy a seat on the American Stock Exchange in 1977. Interactive Brokers records that he applied computerized mathematical models to options pricing and spent the following decade automating market-making across stocks, options and futures. [1][2]
Building an electronic brokerage
Peterffy's market-making operation evolved into a broader electronic trading business, and Interactive Brokers was formed in 1993 as exchanges increasingly moved toward electronic execution. His fortune grew from the ownership and expansion of that trading and brokerage infrastructure rather than from an inherited operating company. [1][3]
The financial mechanism is retained ownership in the brokerage and market-making platform he built over decades. Interactive Brokers' customer assets, trading volume and corporate value describe the scale of the business, but only Peterffy's personal ownership interest belongs on his own balance sheet. [1][3]
Sources for background
Sources reviewed Sep 15, 2026.
- Executive Profiles · Interactive Brokers
- This Self-Made Wall Street Billionaire Has Never Read A Single Investment Book · Forbes · Dec 22, 2023
- Thomas Peterffy · Forbes · Jul 15, 2026
Comparable Finance & Investments billionaires
Similar Finance & Investments billionaires by estimated net worth.
.jpg?width=512)