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Form 8-K

sec.gov

8-K — Interactive Brokers Group, Inc.

Accession: 0001381197-26-000135

Filed: 2026-07-31

Period: 2026-07-31

CIK: 0001381197

SIC: 6211 (SECURITY BROKERS, DEALERS & FLOTATION COMPANIES)

Item: Other Events

Item: Financial Statements and Exhibits

Documents

8-K — ibkr-20260731.htm (Primary)

EX-5.3 (ibkr-ex5_3.htm)

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8-K

8-K (Primary)

Filename: ibkr-20260731.htm · Sequence: 1

8-K

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 31, 2026

Interactive Brokers Group, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-33440

30-0390693

(State or Other Jurisdiction

of Incorporation)

(Commission File Number)

(IRS Employer

Identification No.)

ONE PICKWICK PLAZA

GREENWICH, Connecticut

06830

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s Telephone Number, Including Area Code: 203 618-5800

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class

Trading

Symbol(s)

Name of each exchange on which registered

Common Stock, par value $.01 per share

IBKR

The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events.

On July 31, 2026, Interactive Brokers Group, Inc. (the "Company") filed a Prospectus Supplement under Rule 424(b)(5) to register up to 920,000 shares of the Company's common stock from its shelf Registration Statement on Form S-3 (Registration Statement No. 333-297857) (the "Registration Statement") filed with the SEC on July 31, 2026. The legal opinion letter of Dechert LLP, counsel to the Company, regarding the validity of the shares is filed as Exhibit 5.3 to this Current Report on Form 8-K. The legal opinion letter is also hereby incorporated by reference into the Registration Statement, as Exhibit 5.3 thereto.

Item 9.01 Financial Statements and Exhibits.

Exhibit No.

Description

5.3

Opinion of Dechert

104

Cover Page Interactive Data File (the cover page XBRL tags are embedded within the Inline XBRL Document).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date:

July 31, 2026

By:

/s/ Paul J. Brody

Paul J Brody

Chief Financial Officer, Treasurer and Secretary

EX-5.3

EX-5.3

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EX-5.3

EXHIBIT 5.3

July 31, 2026

Interactive Brokers Group, Inc.

One Pickwick Plaza

Greenwich, Connecticut 06830

Re: Form S-3 Registration Statement and Prospectus Supplement

Ladies and Gentlemen:

We have acted as special counsel to Interactive Brokers Group, Inc., a Delaware corporation (the “Company”), in connection with the preparation and filing of (1) a Registration Statement on Form S-3 (as amended on the date hereof, the “Registration Statement”) filed on July 31, 2026 by the Company as an automatic shelf registration statement with the Securities and Exchange Commission (the “Commission”) under the Securities Act of 1933, as amended (the “Act”); and (2) the Company’s prospectus supplement relating to the issuance and sale by the Company of up to 920,000 shares (the “Offered Shares”) of Class A common stock, par value $0.01 per share, of the Company (the “Common Shares”), to be filed by the Company with the Commission on or about the date of this opinion pursuant to Rule 424(b)(5) under the Act (together with the Company’s base prospectus included in the Registration Statement, collectively, the “Prospectus”). The Registration Statement relates to the issuance and sale from time to time on a delayed or continuous basis, pursuant to Rule 415 of the General Rules and Regulations promulgated under the Act, of an indeterminate number of Common Shares. The board of directors of the Company (the “Board”) has deemed it advisable and in the best interest of the Company and its shareholders to issue and register the Offered Shares and to use the Offered Shares for promotions that are designed to attract new customers.

This opinion is being delivered in accordance with the requirements of Item 601(b)(5) of Regulation S-K under the Act, and no opinion is expressed herein as to any matter pertaining to the contents of the Registration Statement or the Prospectus, other than as to the validity of the Offered Shares as set forth below.

We have reviewed such records, documents, agreements and certificates, and examined such questions of law, as we have considered necessary or appropriate to express the opinions set forth below. In making our examination of records, documents, agreements and certificates, we have assumed the authenticity of the same, the correctness of the information contained therein, the genuineness of all signatures, the authority of all persons entering and maintaining records or executing documents, agreements and certificates, and the conformity to authentic originals of all items submitted to us as copies (whether certified, conformed, photostatic or by other electronic means) of records, documents, agreements or certificates. In rendering the opinions set forth below, we have relied as to factual matters upon certificates of public officials, certificates and other assurances of officers and representations of the Company.

We have further assumed that the Offered Shares will be issued and sold in the manner stated in the Registration Statement and the Prospectus and in compliance with the applicable provisions of the Act and the rules and regulations of the Commission thereunder, and the securities or blue sky laws of various states.

Based upon and subject to the foregoing and to the other assumptions, qualifications, limitations and exceptions set forth herein, we are of the opinion that the Offered Shares have been duly authorized for issuance by the Company and, when issued and delivered against receipt by the Company of payment of the agreed-upon consideration therefor as provided in the Prospectus, will be validly issued, fully paid and nonassessable.

The opinions expressed herein are limited to the Delaware General Corporation Law, and we express no opinion herein concerning any other laws, rules or regulations (including, without limitation, the application of the securities or “blue sky” laws of any state to the offer and/or sale of the Offered Shares).

We hereby consent to the filing of this opinion with the Commission as an exhibit to a Current Report on Form 8-K of the Company. In giving this consent, we do not thereby admit that we are within the category of persons whose consent is required under Section 7 of the Act or the rules and regulations of the Commission promulgated thereunder. This opinion is expressed as of the date hereof, and we disclaim any undertaking to advise you of any subsequent changes in the facts stated or assumed herein or of any subsequent changes in applicable laws, even where the Common Shares may be issued from time to time on a delayed or continuous basis.

Sincerely,

/s/ Dechert LLP

Dechert LLP

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