ADTRAN investors saw shares fall after preliminary Q2 2026 results missed guidance and the Company pointed to a delayed single-customer project. The investigation focuses on whether ADTRAN adequately disclosed risks relating to customer project timing.

NEW YORK, July 27, 2026 /PRNewswire/ -- ADTRAN Holdings (NASDAQ: ADTN) shares fell approximately 15% on July 22, 2026 after the Company announced preliminary unaudited Q2 2026 revenue and margin below prior guidance, citing a delay on a single-customer project. ADTN investors who suffered losses are encouraged to submit your information. You may also contact Joseph E. Levi, Esq. by telephone at (888) SueWallSt.

ADTRAN reported preliminary Q2 2026 revenue of $280 million to $282 million, below its prior guidance of $283 million to $303 million. The Company also projected non-GAAP operating margin of approximately 3.5% to 4.0%, below prior guidance of 5% to 9%. ADTRAN attributed the shortfall to a delay on a single-customer project.

The investigation focuses on whether investors were adequately informed about risks relating to customer project timing before the stock drop. On the November 4, 2025 earnings call, CFO Timothy Santo stated that one customer contributed more than 10% of total revenue during the third quarter. The later Q2 2026 shortfall was tied by the Company to a delay involving a single customer project.

If you lost money in ADTN after the Q2 2026 preliminary results missed prior guidance, act now. Click here to learn more. You may also contact Joseph E. Levi, Esq. by telephone at (888) SueWallSt.

WHY SUEWALLST: SueWallSt is powered by Levi & Korsinsky LLP. Levi & Korsinsky LLP has established itself as a nationally-recognized securities litigation firm that has secured hundreds of millions of dollars for aggrieved shareholders and built a track record of winning high-stakes cases. The firm has extensive expertise representing investors in complex securities litigation and a team of over 70 employees to serve our clients. For seven years in a row, Levi & Korsinsky has ranked in ISS Securities Class Action Services' Top 50 Report as one of the top securities litigation firms in the United States.

Frequently Asked Questions About the ADTN Investigation

Q: What is the ADTN investigation about?A: The investigation concerns ADTRAN Holdings (NASDAQ: ADTN) and potential securities law violations related to statements about Q2 2026 revenue, operating margin, and customer-project timing. Shares fell approximately 15% after the Company announced preliminary Q2 2026 results below prior guidance and cited a delay on a single-customer project.

Q: Who is eligible to participate in the ADTN investigation?A: Investors who purchased ADTN stock or securities and suffered financial losses may be eligible. Eligibility is based on purchase date and documented losses -- not on whether you still hold the shares.

Q: Which statements are being reviewed in the ADTN investigation?A: The investigation concerns statements regarding ADTRAN's Q2 2026 outlook, customer concentration, and the single-customer project delay that the Company later cited when preliminary results came in below guidance.

Q: What documents do I need to participate?A: Brokerage statements or trade confirmations showing purchase dates, share quantities, prices paid, and any subsequent sale dates and prices.

Q: What is a lead plaintiff and why does it matter?A: If the investigation proceeds to legal action, a lead plaintiff is the investor a court may appoint to represent affected investors. Lead plaintiffs are typically investors with the largest documented losses.

Q: What if I already sold my ADTN shares -- can I still recover losses?A: Yes. Eligibility is based on when you purchased, not whether you still hold the shares. Investors who bought ADTN and sold at a loss may still participate in the investigation.

Q: What does it cost me to participate?A: There is no upfront cost to participate. Securities investigations and any resulting actions are generally handled on a contingency basis. No upfront fees, no retainer, and no out-of-pocket costs.

CONTACT:\

Levi & Korsinsky, LLP\

Joseph E. Levi, Esq.\

33 Whitehall Street, 27th Floor\

New York, NY 10004\

jlevi@SueWallSt.com\

Tel: (888) SueWallSt\

Fax: (212) 363-7171

Attorney Advertising. Prior results do not guarantee similar outcomes.

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SOURCE SueWallSt.com