ADTRAN Holdings, Inc. 10-Q

ITEM 5. OTHER INFORMATION (a) Not applicable (b) Not applicable (c) Insider Trading Arrangements James D. Wilson, Jr ., our Chief Revenue Officer , adopted a Rule 10b5-1 trading arrangement (as defined in Item 408 of Regulation S-K) on May 19, 2026 . Mr. Wilson's trading arrangement covers the sale of 56,068 shares of the Company’s common stock, and it is scheduled to terminate on the earlier of (i) May 31, 2027 and (ii) the date that all shares are sold. Other than as disclosed above, during the fiscal quarter ended June 30, 2026, none of the Company’s directors or executive officers adopted or terminated any contract, instruction or written plan for the purchase or sale of Company securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) or any “non-Rule 10b5-1 trading arrangement” as defined in Item 408 of Regulation S-K. 53 ITEM 6. EXHIBITS Exhibits. Exhibit No. Description 3.1 Amended and Restated Certificate of Incorporation of ADTRAN Holdings, Inc. (incorporated by reference to Exhibit 3.1 to the Company's Form 8-K filed July 8, 2022) 3.2 Certificate of Amendment to the Amended and Restated Certificate of Incorporation of ADTRAN Holdings, Inc. (incorporated by reference to Exhibit 3.1 to the Company's Form 8-K filed May 18, 2026) 3.3 Second Amended and Restated Bylaws of ADTRAN Holdings, Inc. (incorporated by reference to Exhibit 3.1 to the Company's Form 8-K filed October 24, 2023) 10.1 Second Amendment to the CEO Employment Agreement, dated April 6, 2026 (incorporated by reference to Exhibit 10.1 to the Company’s Form 8-K filed April 7, 2026) 10.2 Form of 2026 3-Year Performance Shares Agreement under the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan (incorporated by reference to Exhibit 10.2 to the Company’s Form 8-K filed April 7, 2026) 10.3 Form of 2026 CEO 3-Year Performance Shares Agreement under the ADTRAN Holdings, Inc. 2024 Employee Stock Incentive Plan (incorporated by reference to Exhibit 10.3 to the Company’s Form 8-K filed April 7, 2026) 10.4 Credit Agreement dated July 21, 2026, by and among ADTRAN Holdings, Inc., as holdings, ADTRAN, Inc. and Adtran Networks SE, as borrowers, JPMorgan Chase Bank, N.A. and J.P. Morgan SE, as administrative agents and the lenders party thereto (incorporated by reference to Exhibit 10.1 to the Company's Form 8-K filed July 23, 2026) 10.5 Guarantee and Collateral Agreement dated July 21, 2026 by and among ADTRAN Holdings, Inc., ADTRAN, Inc. and certain subsidiaries party thereto in favor of JPMorgan Chase Bank, N.A. (incorporated by reference to Exhibit 10.2 to the Company's Form 8-K filed July 23, 2026) 10.6 Share Pledge Agreement dated July 21, 2026 by and among ADTRAN Holdings, Inc., Adtran Networks SE, and JPMorgan Chase Bank, N.A., as administrative agent (incorporated by reference to Exhibit 10.3 to the Company's Form 8-K filed July 23, 2026) 31.1* Certification of the Chief Executive Officer pursuant to Rule 13a-14(a)/15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 31.2* Certification of the Chief Financial Officer pursuant to Rule 13a-14(a)/15d-14(a), as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002 32* Section 1350 Certifications 101 The following financial statements from the Company’s Quarterly Report on Form 10-Q for the quarter ended June 30, 2026, formatted in Inline XBRL: (i) Condensed Consolidated Balance Sheets as of June 30, 2026 and December 31, 2025; (ii) Condensed Consolidated Statements of Loss for the three and six months ended June 30, 2026 and 2025; (iii) Condensed Consolidated Statements of Comprehensive (Loss) Income for the three and six months ended June 30, 2026 and 2025; (iv) Condensed Consolidated Statements of Changes in Equity for the three and six months ended June 30, 2026 and 2025; (v) Condensed Consolidated Statements of Cash Flows for the six months ended June 30, 2026 and 2025; and (vi) Notes to Condensed Consolidated Financial Statements 104 Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101) * Filed herewith. 54 SIGNA TURE 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, thereunto duly authorized. ADTRAN Holdings, Inc. Date: August 4, 2026 /s/ Timothy Santo Timothy Santo Senior Vice President of Finance and Chief Financial Officer (Principal Financial Officer and Duly Authorized Officer) 55