
26. Thomas Peterffy – $17.2 billion
Peterffy is one of the most impressive rags to riches stories on this list, especially since he came to the US as a young immigrant. Peterffy fled to the US in 1965 when he was only 21. He was the son of Hungarian aristocrats who lost all of their money to the redistribution enforced by the Soviet Union in its takeover of Hungary. He essentially arrived in the US with the clothes on his back and no ability to receive material support from his family. Despite these tough beginnings, Peterffy always had an entrepreneurial spirit, notably selling gum to his high school classmates in Hungary at a massive 150% markup.

Once in the US, Peterffy attended New York University but ultimately dropped out to follow his entrepreneurship dreams. Peterffy worked as an engineer for a stable income source while working towards becoming a trader. He saved up enough money from his engineering salary to buy a seat on the US Stock Exchange. He eventually built Interactive Brokers in 1993 after gaining experience as a market maker and developing algorithms regarding stock trading. Interactive Brokers is currently the largest electric trading platform globally by volume of daily average revenue trades per day.