STOCK TITAN

CTO at ADTRAN (NASDAQ: ADTN) sells 148K shares after option exercise

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

ADTRAN Holdings Chief Technology Officer Christoph Glingener reported a series of option exercises and related share sales in ADTRAN Holdings, Inc. common stock. On May 7 and 8, 2026, he exercised stock options covering a total of 148,392 shares at exercise prices of $7.01 and $12.17 per share, then sold the same number of shares in open-market transactions at weighted average prices in the mid‑teens per share, including a single trade at $15.00 per share. The transactions were executed under a Rule 10b5-1 trading plan adopted on December 12, 2025. Following these trades, he directly owns 46,645 common shares and holds remaining stock options tied to 85,383 underlying shares at a $19.08 exercise price expiring on May 14, 2029.

Positive

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Insider Glingener Christoph
Role Chief Technology Officer
Sold 148,392 shs ($2.22M)
Type Security Shares Price Value
Exercise Stock Option 22,277 $0.00 --
Exercise Common Stock 22,277 $12.17 $271K
Sale Common Stock 22,277 $15.00 $334K
Exercise Stock Option 41,220 $0.00 --
Exercise Stock Options 84,895 $0.00 --
Exercise Common Stock 41,220 $7.01 $289K
Sale Common Stock 41,220 $14.73 $607K
Exercise Common Stock 84,895 $12.17 $1.03M
Sale Common Stock 84,895 $15.06 $1.28M
holding Stock Option -- -- --
Holdings After Transaction: Stock Option — 0 shares (Direct, null); Common Stock — 68,922 shares (Direct, null); Stock Options — 22,277 shares (Direct, null)
Footnotes (1)
  1. 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. 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. 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. These shares were sold in a single transaction at $15.00 per share. The stock option vested and was fully exercisable. The stock option vests on May 15, 2026, which is the fourth anniversary of the date of the grant.
Shares sold 148,392 shares Total common shares sold in open-market transactions on May 7-8, 2026
Option exercise prices $7.01 and $12.17 per share Exercise prices for stock options converted into common shares
Sale price range $14.355–$15.69 per share Weighted average sale price ranges for multiple transactions
Single sale price $15.00 per share Price for a single reported common stock sale
Shares held after transactions 46,645 shares Direct ADTRAN common stock ownership following all reported trades
Remaining option exercise price $19.08 per share Exercise price of remaining stock option position expiring May 14, 2029
Remaining underlying option shares 85,383 shares Underlying common shares for remaining stock option holding
Net buy/sell shares -148,392 shares Net share change across buy/sell activity, reported as net-sell
Rule 10b5-1 trading plan regulatory
"The transactions reported on this Form 4 were effectuated pursuant to a Rule 10b5-1 trading plan adopted by the reporting person"
A Rule 10b5-1 trading plan is a pre-arranged schedule that allows company insiders to buy or sell stock at specific times, even if they have inside information. It helps prevent accusations of unfair trading by making these transactions look planned and transparent, rather than sneaky or illegal.
weighted average price financial
"The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions"
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
stock option financial
"The stock option vested and was fully exercisable."
A stock option is a contract that gives you the right to buy or sell a company's stock at a specific price within a certain time frame. People use them to potentially make money if the stock's price moves favorably or to protect against losses. It's like holding a coupon that can be used to buy or sell stock at a set price later on.
open-market sale financial
"transaction_action": "open-market sale""
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
SEC Form 4
FORM 4UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number:3235-0287
Estimated average burden
hours per response:0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
X
Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.
1. Name and Address of Reporting Person*
Glingener Christoph

(Last)(First)(Middle)
C/O ADTRAN HOLDINGS, INC.
901 EXPLORER BOULEVARD

(Street)
HUNTSVILLE ALABAMA 35806-2807

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
ADTRAN Holdings, Inc. [ ADTN ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
Chief Technology Officer
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/07/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm filed by One Reporting Person
Form filed by More than One Reporting Person
4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year)2A. Deemed Execution Date, if any (Month/Day/Year)3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeVAmount(A) or (D)Price
Common Stock05/07/2026M(1)41,220A$7.0187,865D
Common Stock05/07/2026S(1)41,220D$14.73(2)46,645D
Common Stock05/07/2026M(1)84,895A$12.17131,540D
Common Stock05/07/2026S(1)84,895D$15.06(3)46,645D
Common Stock05/08/2026M(1)22,277A$12.1768,922D
Common Stock05/08/2026S(1)22,277D$15(4)46,645D
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year)3A. Deemed Execution Date, if any (Month/Day/Year)4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year)7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option$7.0105/07/2026M(1)41,220 (5)05/14/2027Common Stock41,220$00D
Stock Options$12.1705/07/2026M(1)84,895 (5)05/14/2028Common Stock84,895$022,277D
Stock Option$12.1705/08/2026M(1)22,277 (5)05/14/2028Common Stock22,277$00D
Stock Option$19.08 (6)05/14/2029Common Stock85,38385,383D
Explanation of Responses:
1. 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.
2. 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.
3. 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.
4. These shares were sold in a single transaction at $15.00 per share.
5. The stock option vested and was fully exercisable.
6. The stock option vests on May 15, 2026, which is the fourth anniversary of the date of the grant.
/s/ Dan Ragsdale, by power of attorney05/11/2026
** Signature of Reporting PersonDate
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transactions did ADTRAN (ADTN) report for CTO Christoph Glingener?

ADTRAN reported that CTO Christoph Glingener exercised stock options and sold 148,392 common shares. The sales occurred in open-market transactions on May 7 and 8, 2026, immediately after exercising options, and were conducted under a pre-arranged Rule 10b5-1 trading plan.

How many ADTRAN (ADTN) shares did the CTO sell and at what prices?

The CTO sold 148,392 ADTRAN common shares. Weighted average sale prices ranged from about $14.355 to $15.69 per share, including a single transaction at $15.00. These prices reflect multiple trades executed over two trading days in the open market.

What option exercise prices were involved in the ADTRAN (ADTN) CTO’s Form 4 filing?

The CTO exercised stock options to acquire 148,392 ADTRAN shares at exercise prices of $7.01 and $12.17 per share. These options were then followed by open-market sales of the same number of shares, effectively converting the option positions into cash equity transactions.

Does the ADTRAN (ADTN) CTO still hold shares after these insider sales?

Yes. After the reported transactions, the CTO directly holds 46,645 ADTRAN common shares. In addition, he retains stock options linked to 85,383 underlying shares with a $19.08 exercise price that expire on May 14, 2029, providing further potential equity exposure.

Were the ADTRAN (ADTN) CTO’s trades made under a Rule 10b5-1 plan?

Yes. The filing states the transactions were effectuated pursuant to a Rule 10b5-1 trading plan adopted on December 12, 2025. Such plans pre-schedule trades, indicating these sales were arranged in advance rather than timed in response to short-term market developments.

What is the remaining option position for the ADTRAN (ADTN) CTO after these trades?

After exercising certain options, the CTO continues to hold a stock option position with an exercise price of $19.08 per share covering 85,383 underlying common shares. This option expires on May 14, 2029, and represents ongoing potential ownership if exercised in the future.