Person profile
Founder and chairman of Interactive Brokers
"Valued as of" is the effective date of the market closes, exchange rates, and filings inside the estimate. "Sources checked" is when the pipeline last verified those sources successfully. A weekend check can confirm a Friday valuation without inventing weekend movement.
As of September 4, 2026, Thomas Peterffy's estimated net worth is about $106.7B(106.7 billion US dollars). That places Thomas Peterffy at #11 among the people Net Worth Leader currently tracks.
This is an estimate of assets minus documented liabilities. It is not a cash balance, and many holdings may be restricted, pledged, illiquid, or difficult to value.
Thomas Peterffy founded the business that became Interactive Brokers in 1977 and pioneered computerized market making before building one of the largest electronic brokerages. Most of his wealth sits in membership interests of the operating company rather than listed shares, so the estimate converts the disclosed economic interest into Class A equivalents.
Peterffy emigrated from Hungary in 1965, bought a seat on the American Stock Exchange in 1977, and automated options trading years before the exchanges did. Interactive Brokers listed in 2007 with an umbrella structure in which his holding company retains most of the economics.
The estimate moves with Interactive Brokers' Class A share price. The 4-for-1 split of June 2025 is reflected in all counts.
Thomas Peterffy's estimate declined mainly because Interactive Brokers Group, Inc. shares decreased from the prior comparable close.
A one-day estimate change is not the same as income, profit, or a realized gain or loss.
| Component | Class | Ownership | Valuation basis | Central value | Supported range | Evidence date | Price date | Sources | Freshness |
|---|---|---|---|---|---|---|---|---|---|
| Interactive Brokers Class A common stock held directlyInteractive Brokers Group, Inc. (IBKR, Class A common stock) | listed equity | direct (6,219,110 units) | Listed close | 576.0 million US dollars | Priced value | [1] Interactive Brokers Group, Inc., 2026 definitive proxy statement (DEF 14A), [2] Daily unadjusted closing prices, chart endpoint | current | ||
| Economic interest in IBG LLC held through IBG Holdings LLC, expressed as Class A equivalentsInteractive Brokers Group, Inc. (IBKR, Class A common stock) | listed equity | modeled (1,145,675,473 units) | Disclosed economic interest | 106.1 billion US dollars | 95.5 billion US dollars to 106.1 billion US dollars | [1] Interactive Brokers Group, Inc., Form 10-K for fiscal 2025, [2] Interactive Brokers Group, Inc., 2026 definitive proxy statement (DEF 14A), [3] Daily unadjusted closing prices, chart endpoint | current |
Liabilities without a documented value are never shown as zero; they are simply not included, and that limitation is part of source coverage below.
100.0% of this profile's modeled gross value is supported by Tier 1 or Tier 2 evidence (primary filings, official documents, licensed market data, or audited accounts). The profile carries a strong coverage label.
The supported range shown in the header reflects documented uncertainty in privately valued components. Priced listed holdings carry no modeled range of their own. Unknown liabilities are not evidence that no liabilities exist. No personal liability is documented for this profile, so none is deducted.
The timeline runs from June 12, 2026 to September 4, 2026; the latest estimate is higher than the first point. Points before August 20, 2026 are labeled modeled reconstructions: today's reviewed ownership records applied to the closing prices of each earlier market date. Published history begins August 20, 2026 and grows one point per completed market date.
| Estimate date | Central estimate | Basis |
|---|---|---|
| 106.7 billion US dollars | Published snapshot | |
| 107.1 billion US dollars | Published snapshot | |
| 102.7 billion US dollars | Published snapshot | |
| 104.1 billion US dollars | Published snapshot | |
| 112.1 billion US dollars | Published snapshot | |
| 103.5 billion US dollars | Published snapshot | |
| 104.3 billion US dollars | Modeled reconstruction | |
| 104.3 billion US dollars | Modeled reconstruction | |
| 108.7 billion US dollars | Modeled reconstruction | |
| 106.0 billion US dollars | Modeled reconstruction | |
| 105.3 billion US dollars | Modeled reconstruction | |
| 105.6 billion US dollars | Modeled reconstruction | |
| 103.4 billion US dollars | Modeled reconstruction | |
| 104.4 billion US dollars | Modeled reconstruction | |
| 101.2 billion US dollars | Modeled reconstruction | |
| 99.1 billion US dollars | Modeled reconstruction | |
| 102.2 billion US dollars | Modeled reconstruction | |
| 102.1 billion US dollars | Modeled reconstruction | |
| 101.1 billion US dollars | Modeled reconstruction | |
| 104.2 billion US dollars | Modeled reconstruction | |
| 99.4 billion US dollars | Modeled reconstruction | |
| 104.7 billion US dollars | Modeled reconstruction | |
| 106.3 billion US dollars | Modeled reconstruction | |
| 105.7 billion US dollars | Modeled reconstruction | |
| 105.7 billion US dollars | Modeled reconstruction | |
| 105.6 billion US dollars | Modeled reconstruction | |
| 104.3 billion US dollars | Modeled reconstruction | |
| 106.2 billion US dollars | Modeled reconstruction | |
| 112.2 billion US dollars | Modeled reconstruction | |
| 110.1 billion US dollars | Modeled reconstruction | |
| 107.8 billion US dollars | Modeled reconstruction | |
| 108.4 billion US dollars | Modeled reconstruction | |
| 109.8 billion US dollars | Modeled reconstruction | |
| 107.6 billion US dollars | Modeled reconstruction | |
| 108.9 billion US dollars | Modeled reconstruction | |
| 110.6 billion US dollars | Modeled reconstruction | |
| 105.2 billion US dollars | Modeled reconstruction | |
| 107.4 billion US dollars | Modeled reconstruction | |
| 100.3 billion US dollars | Modeled reconstruction | |
| 101.6 billion US dollars | Modeled reconstruction | |
| 103.5 billion US dollars | Modeled reconstruction | |
| 106.2 billion US dollars | Modeled reconstruction | |
| 106.9 billion US dollars | Modeled reconstruction | |
| 109.1 billion US dollars | Modeled reconstruction | |
| 111.5 billion US dollars | Modeled reconstruction | |
| 110.6 billion US dollars | Modeled reconstruction | |
| 109.5 billion US dollars | Modeled reconstruction | |
| 107.2 billion US dollars | Modeled reconstruction | |
| 106.8 billion US dollars | Modeled reconstruction | |
| 104.6 billion US dollars | Modeled reconstruction |
On paper, Thomas Peterffy's estimated net worth is equivalent to about 2,140,000 average-priced new vehicles.
Reference value $49,855, effective 2026-07-31. Kelley Blue Book / Cox Automotive
Uses the Kelley Blue Book and Cox Automotive industry estimate of the average new-vehicle transaction price for July 2026. It is an estimate of what buyers paid, not a list price.
Spending this estimate over a full century would take about $34 every second, around the clock.
Constant spend rate over exactly 100 years. Net Worth Leader formula
Divides the estimate evenly across every second of 100 years. It is arithmetic, not a spending plan.
Split evenly across every US resident, the estimate works out to about $312 per person.
Cited population 342,000,000, effective 2025-07-01. U.S. Census Bureau
Divides the estimate evenly across the Census Bureau's July 1, 2025 resident population estimate. It is arithmetic, not a policy proposal, and the assets could not be distributed at the displayed value.
These three comparisons are stable for this profile.Browse the full perspective catalog orcompare Thomas Peterffy with someone else.
Interactive Brokers' 2025 Form 10-K states that Mr. Peterffy and his affiliates own approximately 91.6 percent of the economic interests in IBG Holdings LLC, which holds 1,250,737,416 IBG LLC membership interests. Multiplying those figures gives 1,145,675,473 Class A equivalents, modeled at Tier 2 with a low case that removes 10 percent for affiliates who are not Mr. Peterffy. Directly held Class A shares come from the March 2026 proxy statement.
Identity facts stored separately for this profile: citizenship United States; residence United States; ranking attribution United States. Attribution reason: Citizen and resident of the United States, where Interactive Brokers is headquartered and listed.
Reviewed by Net Worth Leader editorial desk on August 20, 2026. General rules live in the methodology.
See something wrong? Report a correction. Evidence is evaluated on its merits, not on who submits it.
