APPLIED OPTOELECTRONICS, INC. 8-K

What Happened

• Applied Optoelectronics, Inc. (AAOI) filed an 8-K reporting that its Audit Committee approved the dismissal of Grant Thornton LLP as the company’s independent registered public accounting firm on May 4, 2026. Grant Thornton remains engaged to perform the review of the company’s consolidated financial statements for the quarter ended March 31, 2026. The Committee also approved the appointment of PricewaterhouseCoopers LLP (PwC) as the company’s independent registered public accounting firm for the fiscal year ending December 31, 2026.
• Grant Thornton’s audit reports for the years ended December 31, 2025 and 2024 contained no adverse opinions or qualifications, and there were no disagreements with Grant Thornton for 2024, 2025 or through May 4, 2026. The filing notes a previously disclosed material weakness in controls over review of technical accounting analysis that was remediated as of December 31, 2025. Grant Thornton furnished a letter dated May 8, 2026; a copy is filed as Exhibit 16.1 to the 8-K.

Key Details

• Audit committee action date: May 4, 2026 (dismissal of Grant Thornton; appointment of PwC).
• Grant Thornton will still perform the March 31, 2026 quarter review despite the dismissal.
• Prior audit reports (2024 and 2025) had no adverse opinions, disclaimers, or unresolved disagreements.
• Previously disclosed material weakness was remediated as of December 31, 2025; PwC had not been consulted on accounting issues during 2024–2026 prior to appointment.

Why It Matters

• A change in independent auditor is material for investors because it can affect audit approach, reporting continuity and investor confidence in financial controls and disclosures.
• The filing provides some reassurance: recent audits were unqualified and the previously disclosed material weakness was reported as remediated. There are no reported disagreements with the outgoing auditor and the outgoing firm will complete the Q1 2026 review.
• Investors should watch for future communications (proxy, 10-Q/10-K) for any changes in audit fees, audit scope, or additional disclosures around accounting controls as PwC begins its engagement.