ITEM 2.02. RESULTS OF OPERATIONS AND FINANCIAL CONDITION. On February 26, 2026 Applied Optoelectronics, Inc. (the “ Company”) issued a press release regarding the Company’s financial results for the fourth quarter ended December 31, 2025. A copy of the Company’s press release is attached as Exhibit 99.1 to this Form 8-K. The information furnished in this Current Report under this Item 2.02 and the exhibits attached hereto shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “ Exchange Act”), or incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

ITEM 9.01. FINANCIAL STATEMENTS AND EXHIBITS. (d) Exhibits Exhibit No. Description 99.1 Press release dated February 26, 2026, issued by Applied Optoelectronics, Inc., filed herewith. ──────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 104 Cover Page Interactive File (the cover page tags are embedded within the Inline XBRL document). 2 SIGNATURES