Interactive Brokers Group, Inc. (commonly known as Interactive Brokers or IBKR) is an American multinational brokerage and financial services company headquartered in Greenwich, Connecticut. Through its subsidiaries, it provides automated trade execution and custody services for stocks, options, futures, foreign exchange, bonds, funds and other products on electronic markets worldwide. Its services include direct market access, clearing, securities lending, margin lending and prime brokerage.
As of June 30, 2026, the company had 5.185 million customer accounts and $930.3 billion in customer equity; customer daily average revenue trades (DARTs) averaged 4.824 million during the second quarter of 2026. It provides access to more than 170 markets and serves customers in more than 200 countries and territories.
The company is chaired by its founder, Thomas Peterffy, and has been led by chief executive Milan Galik since 2019. Interactive Brokers ranked 410th on the 2026 Fortune 500. In August 2025, it joined the S&P 500.
The company traces its roots to T.P. & Co., a market maker founded by Peterffy in 1978 and renamed Timber Hill Inc. in 1982. The business pioneered the use of fair-value pricing sheets, handheld trading computers and automated algorithmic trading. Interactive Brokers was incorporated as a broker-dealer in 1993, and its electronic brokerage operations were separated from Timber Hill's market-making business. The group went public in 2007, sold the Timber Hill business in 2017, introduced cryptocurrency trading in 2021 and launched the ForecastEx prediction market in 2024.
History
In 1977, Thomas Peterffy left his job designing commodity trading software for Mocatta Metals, and bought a seat on the American Stock Exchange (AMEX) as an individual market maker. The following year, he formed his first company, named T.P. & Co., to expand trading activities to several members under badge number 549. At the time, trading used an open outcry system. Peterffy developed algorithms to determine the best prices for options and used them on the trading floor. The firm became the first to use daily printed fair value pricing sheets. In 1979, the company expanded to employ four traders, three of whom were AMEX members. In 1982, Peterffy renamed T.P. & Co. to Timber Hill Inc.; he named it after a road to a favorite retreat, one of his properties on Hutchin Hill Road in Woodstock, New York.
By 1983, Peterffy was sending orders to the floor from his upstairs office; he devised a system to read the data from a Quotron machine by measuring the electric pulses in the wire and decoding them. The data would then be sent through Peterffy's trading algorithms, and then Peterffy would call down the trades. After pressure to become a true market maker and keep constant bids and offers, Peterffy knew that he would need his employees to monitor market movements closely, and that handheld computers would help. At the time, the AMEX didn't permit computers on the trading floor. As a result, Peterffy had an assistant deliver market information from his office in the World Trade Center. In November 1983, he convinced the exchange to allow computer use on the floor.
In 1983, Peterffy sought to computerize the options market, and he first targeted the Chicago Board Options Exchange (CBOE). At the time, brokers still used fair value pricing sheets, which were by then updated once or twice a day. In 1983, Timber Hill created the first handheld computers used for trading. As Peterffy explained in a 2016 interview, the battery-powered units had touch screens for the user to input a stock price and it would produce the recommended option prices, and it also tracked positions and continually repriced options on stocks. However, he immediately encountered opposition from the heads of the exchange. When he first brought a by device to the exchange floor, a committee in the exchange told him it was too big. When he made the device smaller, the committee stated that no analytic devices were allowed to be used on the exchange floor. Effectively blocked from using the CBOE, he sought to use his devices in other exchanges.
Also in 1983, Timber Hill expanded to 12 employees and began trading on the Philadelphia Stock Exchange. In 1984, Timber Hill began coding a computerized stock index futures and options trading system and, in February 1985, Timber Hill's system and network was brought online. The system was designed to centrally price and manage risk on a portfolio of equity derivatives traded in multiple locations around the country. In 1985, Peterffy introduced his computer system to the New York Stock Exchange (NYSE), which allowed it. However, the stock exchange only allowed it to be used at trading booths several yards away from where transactions were executed. Peterffy responded by designing a code system for his traders to read colored bars emitted in patterns from the video displays of computers in the booths. This led the exchange and other members to suspect insider trading. Timber Hill responded by distributing instructions throughout the exchange, explaining how to read the displays. In response, the exchange required the company to turn the screens away from the trading floor, which prompted Peterffy to hire a clerk to communicate with the traders via hand signals. Eventually computers were allowed on the trading floor.
Timber Hill joined the Options Clearing Corporation in 1984, the New York Futures Exchange in 1985, and the Pacific Stock Exchange and the options division of the NYSE the following year. Also in 1985, the firm joined and began trading on the Chicago Mercantile Exchange, the Chicago Board of Trade and the Chicago Board Options Exchange. In 1986, the company moved its headquarters to the World Trade Center to control activity at multiple exchanges. Peterffy again hired workers to sprint from his offices to the exchanges with updated handheld devices, which he later superseded with phone lines carrying data to computers at the exchanges. Peterffy later built miniature radio transmitters into the handhelds and the exchange computers to allow data to automatically flow to them.
In 1987, Timber Hill joined the National Securities Clearing Corporation and the Depository Trust Company (now merged as the Depository Trust & Clearing Corporation). By 1987, Timber Hill had 67 employees and had become self-clearing in equities. In 1987, the CBOE was about to close down its S&P 500 options market due to the options not attracting sufficient trader interest. In response, Peterffy pledged that Timber Hill would make tight markets in the product for a year if the exchange would allow the traders to use handheld computers on the trading floor. The exchange agreed, and more traders were attracted by the change in pricing. In 1990, Timber Hill Deutschland GmbH was incorporated in Germany, and shortly thereafter began trading equity derivatives at the Deutsche Terminbörse (DTB), marking the first time that Timber Hill used one of its trading systems on a fully automated exchange. In 1992, Timber Hill began trading at the Swiss Options and Financial Futures Exchange, which merged with DTB in 1998 to become Eurex. At that time, Timber Hill had 142 employees.
While Peterffy was trading on the Nasdaq in 1987, he created the first fully automated algorithmic trading system. It consisted of an IBM computer that would pull data from a Nasdaq terminal connected to it and carry out trades on a fully automated basis. The machine, for which Peterffy wrote the software, worked faster than a trader could. Upon inspection, the Nasdaq banned direct interface with the terminal, and required trades to be typed in manually. Peterffy and his team designed a system with a camera to read the terminal, a computer to decode the visual data, and mechanical fingers to type in the trade orders, which was then accepted by the Nasdaq.
1993 to 2000 Interactive Brokers Inc. was incorporated in 1993 as a U.S. broker-dealer, to provide technology developed by Timber Hill for electronic network and trade execution services to customers.
In 1994, Timber Hill Europe began trading at the European Options Exchange, the OM Exchange and the London International Financial Futures and Options Exchange. Also in 1994, Timber Hill Deutschland became a member of the Belgium Futures and Options Exchange, IB became a member of the New York Stock Exchange, and the Timber Hill Group LLC was formed as a holding company of Timber Hill and IB's operations. Timber Hill UK Ltd was incorporated in November 1994.
In 1995, Timber Hill France S.A. was incorporated and began making markets at the Marché des Options Négociables de Paris (a subsidiary of Euronext Paris) and the Marché à Terme International de France futures exchange. Also in 1995, Timber Hill Hong Kong began market making at the Hong Kong Futures Exchange and IB created its primary trading platform Trader Workstation and executed its first trades for public customers.
In 1996, Timber Hill Securities Hong Kong Limited was incorporated and began trading at the Hong Kong Stock Exchange. In the next year, Timber Hill Australia Pty Limited was incorporated in Australia, and Timber Hill Europe began trading in Norway and became a member of the Austrian Derivatives Exchange. By 1997, Timber Hill had 284 employees. In 1998, Timber Hill Canada Company was formed, and IB began to clear online trades for retail customers connected directly to Globex to trade S&P 500 futures.
In 1999, IB introduced a smart order routing linkage for multiple-listed equity options and began to clear trades for its customer stocks and equity derivatives trades. Also in that year, Goldman Sachs attempted to purchase the company and was rejected.
In 2000, Interactive Brokers (U.K.) Limited was formed and Timber Hill became a primary market maker on the International Securities Exchange (ISE).
2001 to 2019
In 2001, the corporate name of the Timber Hill Group LLC was changed to Interactive Brokers Group LLC, which at the time handled 200,000 trades per day. In 2002, Interactive Brokers, along with the Bourse de Montréal and the Boston Stock Exchange, created the Boston Options Exchange. Also in 2002, the company introduced Mobile Trader and an application programming interface for customers and developers to integrate their mobile phone systems with the IB trading system. Also in 2002, Timber Hill became the major market maker for the newly introduced U.S. single-stock futures.
In 2003, the company expanded its trade execution and clearing services to include Belgian index options and futures, Canadian stocks, equity/index options and futures, Dutch index options and futures, German equity options, Italian index options and futures, Japanese index options and futures, and U.K. equity options. In 2004, the company introduced direct market access to its customers on the Frankfurt Stock Exchange and the Börse Stuttgart. In the same year, IB upgraded its account management system and Trader Workstation, adding real-time data including charts, scanners, fundamental analytics, and tools to the platform.
In 2005, the company launched its forex trading platform IdealPro (now Ideal FX). At that point, Interactive Brokers was one of the largest private securities firms in the United States with $2 billion in capital. It handled 20% of total options volume in the US and 16% worldwide.
In 2006, the IB Options Intelligence Report was launched to report on unusual concentrations of trading interests and changing levels of uncertainty in the option markets. Also that year, IBG took stakes in OneChicago, the ISE Stock Exchange, and the CBOE Stock Exchange. Later in 2006, Interactive Brokers began offering penny-priced options.