Interactive Brokers Group Announces Strong Second Quarter Results.

Reports Income Before Taxes and Minority Interest of $259.3 Million on $395.4 Million in Net Revenues, Earnings Per Share of $0.44

GREENWICH, Conn. -- Interactive Brokers Group, Inc. (NASDAQ GS: IBKR) an automated global electronic market maker and broker, today reported diluted earnings per share of $0.44 for the quarter ended June 30, 2008, compared to pro forma diluted earnings per share of $0.28 for the same period in 2007.

Net revenues were $395.4 million and income before income taxes and minority interest was $259.3 million for the quarter, compared to net revenues of $294.7 million and income before income taxes of $164.5 million for the same period in 2007.

Business Highlights

* Diluted earnings per share increased by 57.1% from the year ago quarter.

* 65.6% pre-tax margin for this quarter.

* Market Making pre-tax income grew 73.3% from the year ago quarter.

* 74.3% Market Making pre-tax margin for this quarter.

* Electronic Brokerage pre-tax income rose 32.4% from the year ago quarter.

* 47.7% Electronic Brokerage pre-tax margin for this quarter.

* Cleared DARTs increased to 285,000, or 50.8%, from the year ago quarter.

"We are pleased to announce a 57% year on year increase in our earnings for the second quarter," said Thomas Peterffy, our Chairman and CEO. "Perhaps the most remarkable development during the quarter was the very substantial increase in futures trading on the part of our customers. We see evidence that our solid financial footing and comprehensive risk controls are attracting customers to us from weaker competitors. These times of financial strain among our broker dealer competitors represent a unique opportunity for us to increase our customer acquisition rates and to widen our technological lead."

Segment Overview

Electronic Brokerage

Electronic Brokerage segment income before income taxes grew 32.4% in the quarter ended June 30, 2008 compared to the same period in 2007. This growth was driven by higher revenues from commission and execution fees and a small increase in net interest income. Pre-tax margin increased from 44.4% in the second quarter of 2007 to 47.7% for this quarter, reflecting leverage from automation. Total DARTs* for cleared and execution-only customers increased 38.1% to 326,000 during the three months ended June 30, 2008, compared to 236,000 during the three months ended June 30, 2007. Cleared DARTs increased by 50.8% to 285,000 for the three months ended June 30, 2008 compared to the same period in 2007.

Market Making

Market Making segment income before income taxes increased 73.3% in the quarter ended June 30, 2008 compared to the same period in 2007. Pre-tax margin expanded to 74.3% in this quarter from 61.5% in the same quarter of 2007. High market volumes and volatility demonstrated the benefits of our automated trading system and integrated real time risk management. Market Making options contract volume in the quarter ended June 30, 2008 increased by 13.1% from the same period in 2007.

*Daily average revenue trades (DARTs) are based on customer orders.

Conference Call Information:

Interactive Brokers Group will hold a conference call with investors today, July 24, 2008, at 5:30 p.m. EDT to discuss its second quarter results. Investors who would like to listen to the conference call live should dial 877-440-5803 (U.S. domestic) and 719-325-4850 (international). The number should be dialed approximately ten minutes prior to the start of the conference call. Ask for the "Interactive Brokers Conference Call."

The conference call will also be accessible simultaneously, and through replays, as an audio webcast through the Investor Relations section of the Interactive Brokers 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 70 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 direct 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.

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