Thomas Peterffy: How an immigrant built a $120 billion automated brokerage

Executive overview

Tomas Peterffy arrived in New York in 1965 with no money and no connections, then built Interactive Brokers into one of the most profitable financial firms on earth. His edge was never trading skill — it was treating markets as a broken system that computers could fix.

The core insight: automate everything, charge less than anyone else, and refuse to sell.

From Budapest to Wall Street

• Born during a Soviet bombing raid in 1944; father fled, mother feared starvation
• Learned capitalism through 19th-century French novels in his grandmother's surviving library
• At 12, cut sticks of gum into five pieces and sold them in the schoolyard; organized scrap metal hunts at 13
• Secured a visa to West Germany at 21, then walked into the US consulate and applied to immigrate
• Arrived in New York December 1965 with a one-way ticket

The automation instinct emerges early

• First job: drafting roadmaps for a highway engineering firm, where 20-minute calculations were routine
• Taught himself the Olivetti Programma 101 — one of the first desktop computers — from a 100-word manual
• Built a library of programs that cut 20-minute calculations to 30 seconds
• Moved into financial consulting through a fellow Hungarian, then met Dr. Henry Jurecki, a bullion trader
• Jurecki asked him to model silver trading; Peterffy built a math-driven pricing system instead of relying on intuition
• By 1976, commanded 80 programmers — one of the largest financial coding operations in the world

Breaking with Jurecki and going independent

• Visited the Chicago Board Options Exchange; saw bid-ask spreads 2-3 dollars wide — inefficiencies far beyond precious metals
• Secretly built a partial differential equation to price options; tested it inside Jurecki's firm and made money on almost every trade
• Jurecki refused to expand into options, preferring to stay a precious metals dealer
• Key lesson absorbed: "I learned an immense amount about how markets worked. The best lesson was to not let my mind become clouded by conventional wisdom."
• Left in 1977 with $200,000 in savings; bought an AMEX seat for $36,000
• Carried computer-generated price sheets folded into his pockets, sorted by stock; other traders watched with "fascination and growing unease"

Building Timber Hill through improvisation

• Lost half his capital on a single bad trade; rebuilt slowly over five years by hedging every position
• Founded Timber Hill in 1982
• After a knee injury confined him to his office, hacked a Quotron data feed by cutting the wire and reading electrical pulses with an oscilloscope
• Hired six tall women to execute floor trades — specialists who had ignored his bids competed to fill their orders
• Invented the first handheld trading computer in 1983: touchscreen devices the size of hardcover books, uploaded with fresh prices each morning
• When NASDAQ demanded all orders be typed manually, built a mechanical arm with metal fingers that typed buy/sell orders faster than any human could
• Achieved the first fully automated trading system on Wall Street in 1987 — 16 years after first describing the vision in Barron's

Interactive Brokers: building for ordinary investors

• Launched Interactive Brokers in 1993 to give retail traders the same technological edge he had built for himself
• For most of the 1990s, it was "an elegant solution to a problem that didn't yet exist" — markets were still analog
• As exchanges digitized around 2000, floor traders who had mocked Peterffy became his customers
• Timber Hill was outpaced by HFT firms spending hundreds of millions on microwave towers; Peterffy chose not to compete — "it was not interesting to me anymore"
• Shut down Timber Hill entirely in 2017 after a 40-year run as the world's largest options market maker
• Took Interactive Brokers public in 2007 via Dutch auction, saving $80 million in bank fees; used the IPO as advertising, not capital-raising

The machine today

• 4 million customers, 700+ billion in client assets, 3,000 employees — mostly engineers
• 2024: $3.7 billion profit on $5.2 billion revenue (71% margin)
• Company taken public at $12 billion; now worth over $120 billion
• Peterffy still owns nearly 70% of the business at age 81
• "Hard work and common sense is my story"
• Has never been to Costco; has never read a business book