Born On Your Day
Thomas Peterffy
danor shtruzman, Public domain, via Wikimedia Commons

billionaireentrepreneurfounderTop tier

Thomas Peterffy

Entrepreneur · Interactive Brokers · born September 30, 1944

$17.1Bolder estimate, as of 2019 · Forbes

XWhatsAppFacebook

About

Thomas Peterffy is a Hungarian-born American billionaire businessman. He is the founder, chairman and the largest shareholder of Interactive Brokers. As of November 2025, his estimated net worth is US$109 billion, making him the 18th richest person in the world.

Adapted from Wikipedia (CC BY-SA 4.0).

Milestones, by age

Dated facts from Wikidata; ages marked “about” come from year-only dates.

  1. ~50Founded Interactive Brokers1994

Reported wealth

Each figure is a dated estimate from the publisher shown; wealth changes, and nothing here is live.

As ofEstimateSource
2019$17.1BForbes · current

Sources

Every fact on this page traces to one of these.

Sources (3)

Also born on September 30

Thomas's most notable birthday twins

Andy Bechtolsheim
billionaire

Andy Bechtolsheim

Entrepreneur · Sun Microsystems · technology

1955 · Germany

$6.6Bolder estimate, as of 2018 · Forbes

Andreas Maria Maximilian Freiherr von Mauchenheim genannt Bechtolsheim is a German electrical engineer, entrepreneur and investor. He co-founded Sun Microsystems in 1982 and was its chief hardware designer.

Norbert Stuhrmann, CC BY-SA 3.0, via Wikimedia Commons

Full profile →

Sources (3)
billionaire

Stephen Cohen

Entrepreneur · Palantir Technologies · software

1982 · United States

$5.4Bolder estimate, as of 2025 · Forbes

Stephen Andrew Cohen is an American computer scientist and entrepreneur best known as a co-founder, president and secretary of Palantir Technologies, a platform for analyzing integration and visualizing data used by governments and businesses.

Full profile →

Sources (3)
Monica Bellucci
actor

Monica Bellucci

Actor

1964 · Italy

Monica Anna Maria Bellucci is an Italian actress who began her career as a fashion model before working in Italian, American, British, and French films.

Paul Katzenberger, CC BY-SA 4.0, via Wikimedia Commons

Sources (2)
Kieran Culkin
actor

Kieran Culkin

Actor

1982 · United States

Kieran Kyle Culkin is an American actor. Known for portraying distasteful yet sympathetic characters across stage and screen, his accolades include an Academy Award, a BAFTA Award, a Primetime Emmy Award, and two Golden Globe Awards.

Raph_PH, CC BY 2.0, via Wikimedia Commons

Full profile →

Sources (2)
Marion Cotillard
actor

Marion Cotillard

Actor

1975 · France

Marion Cotillard is a French actress who has appeared in both mainstream and independent European and Hollywood productions. She is the recipient of various accolades, including an Academy Award, a British Academy Film Award, two César Awards, and a Golden Globe Award.

Canal22, CC BY 3.0, via Wikimedia Commons

Full profile →

Sources (2)