ADTN

SEC source: 0001193125-26-342317 · ownership.xml · nonDerivative · entry 1

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 83,953

SEC source: 0001193125-26-340206 · ownership.xml · nonDerivative · entry 1

Santo Timothy P · CIK 0001974835 · SVP of Finance; CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 59,924

SEC source: 0001193125-26-320947 · ownership.xml · nonDerivative · entry 1

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 56,029

F1 · kind: These shares represent the vesting of performance stock units that were awarded pursuant to a grant on May 24, 2023 under the Amended and Restated ADTRAN Holdings, Inc. 2020 Employee Stock Incentive Plan.

SEC source: 0001193125-26-296161 · ownership.xml · nonDerivative · entry 1

DelSanto Anne · CIK 0001770310 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 4,399

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-236824 · ownership.xml · nonDerivative · entry 2

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 132,808.486

F2 · kind: The reporting person transferred 10,469 shares of the Issuer's common stock to a donor-advised fund sponsored by a charitable organization under Section 501(c)(3) of the Internal Revenue Code.

SEC source: 0001193125-26-236824 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 143,277.486

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.69 to $14.765, inclusive. The reporting person undertakes to provide to ADTRAN Holdings, Inc. (the Issuer), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001193125-26-216692 · ownership.xml · derivative · entry 9

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 22,277 shares

Expires 2028-05-14

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F5 · derivative.exercise_date: The stock option vested and was fully exercisable.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 6

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 46,645

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F4 · price: These shares were sold in a single transaction at $15.00 per share.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 5

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 68,922

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

SEC source: 0001193125-26-216692 · ownership.xml · derivative · entry 8

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 22,277

Underlying: Common Stock · 84,895 shares

Expires 2028-05-14

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F5 · derivative.exercise_date: The stock option vested and was fully exercisable.

SEC source: 0001193125-26-216692 · ownership.xml · derivative · entry 7

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 0

Underlying: Common Stock · 41,220 shares

Expires 2027-05-14

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F5 · derivative.exercise_date: The stock option vested and was fully exercisable.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 4

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 46,645

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.00 to $15.69, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within this range.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 3

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 131,540

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 2

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 46,645

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

F2 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.355 to $15.69, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within this range.

SEC source: 0001193125-26-216692 · ownership.xml · nonDerivative · entry 1

Glingener Christoph · CIK 0001943622 · Chief Technology Officer

10b5-1 filing: Plan reported

Ownership: Direct

Disclosed balance after: 87,865

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · kind: The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on December 12, 2025.

SEC source: 0001193125-26-142016 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 152,609.486

F1 · kind: Represents a grant of restricted stock units that vest in four equal and annual installments beginning on the first anniversary date of the grant.

SEC source: 0001193125-26-142013 · ownership.xml · nonDerivative · entry 1

Santo Timothy P · CIK 0001974835 · SVP of Finance; CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 53,345

F1 · kind: Represents a grant of restricted stock units that vest in four equal and annual installments beginning on the first anniversary date of the grant.

SEC source: 0001193125-26-142009 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 1,126,553.51

F1 · kind: Represents a grant of restricted stock units that vest in four equal and annual installments beginning on the first anniversary date of the grant.

SEC source: 0001193125-26-119867 · ownership.xml · nonDerivative · entry 1

Santo Timothy P · CIK 0001974835 · SVP of Finance; CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 25,093

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-093954 · ownership.xml · nonDerivative · entry 1

Jacqueline Hourigan Rice · CIK 0001637150 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 13,809

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $10.24 to $10.37, inclusive. The reporting person undertakes to provide to ADTRAN Holdings, Inc. (the Issuer), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001193125-26-024827 · ownership.xml · nonDerivative · entry 2

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 125,233.486

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-024818 · ownership.xml · nonDerivative · entry 2

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 939,904.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-027417 · ownership.xml · nonDerivative · entry 2

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 127,923.486

F2 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted performance stock units.

SEC source: 0001193125-26-027417 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 129,010.486

F1 · kind: These shares represent the vesting of performance stock units that were awarded pursuant to a grant on January 20, 2023 under the Amended and Restated ADTRAN Holdings, Inc. 2020 Employee Stock Incentive Plan.

SEC source: 0001193125-26-027411 · ownership.xml · nonDerivative · entry 2

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 955,470.51

F2 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted performance stock units.

SEC source: 0001193125-26-027411 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 967,877.51

F1 · kind: These shares represent the vesting of performance stock units that were awarded pursuant to a grant on January 20, 2023 under the Amended and Restated ADTRAN Holdings, Inc. 2020 Employee Stock Incentive Plan.

SEC source: 0001193125-26-031745 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 127,701.486

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted performance stock units.

F2 · shares: On January 28, 2026, the Reporting Person filed a Form 4 which inadvertently understated the number of shares withheld for taxes in connection with the vesting event reported therein. This amendment is being filed to correct the number of shares withheld and the total number of shares directly held by the Reporting Person following such withholding.

F2 · balance_after: On January 28, 2026, the Reporting Person filed a Form 4 which inadvertently understated the number of shares withheld for taxes in connection with the vesting event reported therein. This amendment is being filed to correct the number of shares withheld and the total number of shares directly held by the Reporting Person following such withholding.

SEC source: 0001193125-26-024827 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 126,231.486

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-024818 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 954,313.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-019464 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 127,458.486

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-019455 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 971,848.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-26-002903 · ownership.xml · nonDerivative · entry 1

Walker Kathryn A · CIK 0001264261 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 98,663

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-002902 · ownership.xml · nonDerivative · entry 1

Theodosopoulos Nikos · CIK 0001605860 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 65,963

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-002901 · ownership.xml · nonDerivative · entry 1

McCray Gregory James · CIK 0001327057 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 72,892.938

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-002900 · ownership.xml · nonDerivative · entry 1

Nair Balan · CIK 0001398905 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 125,373

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-002898 · ownership.xml · nonDerivative · entry 1

HUSS H FENWICK · CIK 0001201037 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 107,600

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-26-002897 · ownership.xml · nonDerivative · entry 1

Jacqueline Hourigan Rice · CIK 0001637150 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 28,215

F1 · kind: Represents a restricted stock award grant that vests in full on the first anniversary of the date of grant.

SEC source: 0001193125-25-303492 · ownership.xml · nonDerivative · entry 1

Santo Timothy P · CIK 0001974835 · SVP of Finance; CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 26,594

SEC source: 0001193125-25-303491 · ownership.xml · nonDerivative · entry 1

Theodosopoulos Nikos · CIK 0001605860 · Director

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 52,154

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $7.75 to $8.00, inclusive. The reporting person undertakes to provide to ADTRAN Holdings, Inc. (the Issuer), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001193125-25-295709 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 982,095.51

F1 · price: The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $7.32 to $7.33, inclusive. The reporting person undertakes to provide to ADTRAN Holdings, Inc. (the Issuer), any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote (1) to this Form 4.

SEC source: 0001193125-25-288073 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 941,167.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0001193125-25-288074 · ownership.xml · nonDerivative · entry 1

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 128,223.486

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-095931 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 944,522.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-054336 · ownership.xml · nonDerivative · entry 1

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 950,185.51

F1 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-042657 · ownership.xml · nonDerivative · entry 1

Santo Timothy P · CIK 0001974835 · SVP of Finance; CFO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 20,444

F1 · kind: Represents a grant of restricted stock units that vest in four equal and annual installments beginning on the first anniversary date of the grant.

SEC source: 0000950170-25-009894 · ownership.xml · nonDerivative · entry 4

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 128,691.486

F4 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-009870 · ownership.xml · nonDerivative · entry 4

Dopfer Ulrich · CIK 0001974355 · Chief Financial Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 48,195

F4 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-009862 · ownership.xml · nonDerivative · entry 4

STANTON THOMAS R · CIK 0001191219 · Director · Chairman & CEO

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 955,593.51

F4 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted restricted stock units.

SEC source: 0000950170-25-009894 · ownership.xml · nonDerivative · entry 3

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 129,536.486

F3 · kind: Represents a grant of restricted stock units that vest in four equal and annual installments beginning on the first anniversary date of the grant. Remarks:

SEC source: 0000950170-25-009894 · ownership.xml · nonDerivative · entry 2

Wilson James Denson Jr · CIK 0001371377 · Chief Revenue Officer

10b5-1 filing: No plan indicated

Ownership: Direct

Disclosed balance after: 115,373.486

F2 · kind: Shares delivered to the Issuer for the payment of withholding taxes due upon the vesting of previously granted performance stock units.