Subsequent Events	3 Months Ended
Mar. 31, 2025
Subsequent Events [Abstract]
Subsequent Events	17. Subsequent Events The Company has evaluated subsequent events for adjustment to or disclosure in its condensed consolidated financial statements through the date the condensed consolidated financial statements were issued. On April 15, 2025, the Company announced its intention to effect a four-for-one forward split of its common stock in the form of a stock dividend to make stock ownership more accessible to investors. On April 14, 2025 and on April 22, 2025, respectively, the Company’s Board of Directors and the Company’s majority stockholder approved by written consent an amendment to Interactive Brokers Group, Inc.’s Amended and Restated Certificate of Incorporation to, among other things, increase the number of authorized shares of common stock to accommodate the stock split. Each record holder of common stock as of the close of market on Monday, June 16, 2025, will receive three additional shares of common stock, to be distributed after the close of market on Tuesday, June 17, 2025. Trading is expected to commence on a split-adjusted basis at market open on Wednesday, June 18, 2025. Except as disclosed above and in Note 4 and Note 13, no other recordable or disclosable events occurred. *****

Tabular disclosure of significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, losses resulting from fire or flood, losses on receivables, significant realized and unrealized gains and losses that result from changes in quoted market prices of securities, declines in market prices of inventory, changes in authorized or issued debt (SEC), significant foreign exchange rate changes, substantial loans to insiders or affiliates, significant long-term investments, and substantial dividends not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

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