Interactive Brokers Group Reports Brokerage Metrics For May 2009

Interactive Brokers Group, Inc. (NASDAQ GS: IBKR) an automated global electronic market maker and broker, today reported its Electronic Brokerage monthly performance metrics for May. Highlights for the month included:

• 357 thousand Daily Average Revenue Trades⁽¹⁾ (DARTs) in May 2009, up 13% from May 2008.
• 699 annualized average cleared DARTs per customer account.
• 120.2 thousand customer accounts, 18% higher than May 2008.
• 50% of all customers from over 140 countries outside the U.S.
• Ending customer equity of $11.3 billion, 10% higher than May 2008.
• Ending customer credit balances of $8.8 billion and customer margin balances of $2.4 billion.

"Our brokerage business has grown to a level where it constitutes a significant part of our overall business and, accordingly, we have decided to begin releasing monthly statistics starting with May. In order to put these figures into context we have also made available the same statistics for each of the prior months starting from the beginning of last year," said Thomas Peterffy, our CEO.

More information, including historical results for each of the above metrics, can be found on the investor relations page of the Company's corporate web site, www.interactivebrokers.com/ir.

About Interactive Brokers Group, Inc.:
Interactive Brokers Group is an automated global electronic market maker and broker specializing in routing orders and executing and processing trades in securities, futures and foreign exchange instruments on more than 80 electronic exchanges and trading venues around the world. As a market maker, we provide liquidity at these marketplaces and, as a broker, we provide professional traders and investors with electronic access to stocks, options, futures, forex, bonds and mutual funds from a single IB Universal Account^SM. Employing proprietary software on a global communications network, Interactive Brokers Group continuously integrates its software with a growing number of exchanges and trading venues into one automatically functioning, computerized platform that requires minimal human intervention.

Cautionary Note Regarding Forward-Looking Statements:
The foregoing information contains certain forward-looking statements that reflect the company's current views with respect to certain current and future events and financial performance. These forward-looking statements are and will be, as the case may be, subject to many risks, uncertainties and factors relating to the company's operations and business environment which may cause the company's actual results to be materially different from any future results, expressed or implied, in these forward-looking statements. Any forward-looking statements in this release are based upon information available to the company on the date of this release. The company does not undertake to publicly update or revise its forward-looking statements even if experience or future changes make it clear that any statements expressed or implied therein will not be realized. Additional information on risk factors that could potentially affect the company's financial results may be found in the company's filings with the Securities and Exchange Commission.

For Interactive Brokers Group, Inc. Media: Andrew Wilkinson, 203-913-1369 or Investors: Deborah Liston, 203-618-4070.