Q1 2026 Quarterly Report (55th FY) Filing — Daeduck Electronics

Summary

Daeduck Co., Ltd., a holding company that earns dividends, management advisory fees, and brand royalties from its subsidiaries, filed its quarterly report for Q1 2026 (Jan 1 - Mar 31). The consolidation scope is unchanged at 10 subsidiaries (2 listed, 8 unlisted), with no additions or removals during the period. Core operating businesses conducted through subsidiaries remain PCB manufacturing and sales as well as SAW filters and RF modules. Sections on corporate history, capital changes, and total shares are omitted per disclosure rules and will appear in the semi-annual or annual report.

Historical Impact

2 past Quarterly Report · ≈ 10-Q events at Daeduck Electronics

Median +5d

-2.51%

Range

-4.33% to -0.68%

Positive outcomes

0/2

Filed	P₀	P₊₅	+5d
Nov 14, 2025	₩10,230	₩10,160	-0.68%
May 15, 2025	₩7,850	₩7,510	-4.33%

Full Translation

Quarterly Report 6.5 Daeduck Co., Ltd. 1 Y 130111-0007608 Quarterly Report (55th Fiscal Year) Fiscal Year: From January 1, 2026 to March 31, 2026 To: Financial Services Commission, Korea Exchange Date of Submission: May 15, 2026 Type of Filing Entity: Listed Stock Corporation Grounds for Exemption: Not applicable Company Name: Daeduck Co., Ltd. CEO: Kim Young-jae Head Office Location: 230 Gangchon-ro, Danwon-gu, Ansan-si, Gyeonggi-do (Tel) 031-8040-0823 (Website) http://www.daeduckholdings.com Person in Charge of Preparation: (Position) Team Leader (Name) Won Jong-sung (Tel) 031-8040-0823 Table of Contents [Confirmation by CEO, etc.] ... 1 I. Overview of the Company ... 2 1. Company Overview ... 2 2. Corporate History ... 4 3. Changes in Capital ... 4 4. Total Number of Shares ... 4 5. Matters Concerning the Articles of Incorporation ... 4 II. Business Content ... 5 1. Business Overview ... 5 2. Major Products and Services ... 6 3. Raw Materials and Production Facilities ... 8 4. Sales and Order Status ... 13 5. Risk Management and Derivative Transactions ... 18 6. Major Contracts and R&D Activities ... 20 7. Other Reference Matters ... 24 III. Financial Matters ... 36 1. Summary Financial Information ... 36 2. Consolidated Financial Statements ... 39 3. Notes to Consolidated Financial Statements ... 46 4. Financial Statements ... 118 5. Notes to Financial Statements ... 123 6. Dividend-Related Matters ... 172 7. Funding through Securities Issuance ... 176 8. Other Financial Matters ... 178 IV. Management's Discussion and Analysis ... 185 1. Cautionary Statement on Forward-Looking Information ... 185 2. Overview ... 185 3. Financial Condition and Operating Results ... 185 4. Liquidity, Funding and Expenditure ... 185 5. Off-Balance-Sheet Transactions ... 185 6. Other Matters Necessary for Investment Decisions ... 185 V. Auditor's Opinion, etc. ... 186 1. External Audit Matters ... 186 2. Internal Control Matters ... 188 VI. Board of Directors and Other Corporate Bodies ... 189 1. Board of Directors ... 189 2. Audit System ... 189 3. General Shareholders' Meeting ... 189 VII. Shareholder Matters ... 195 VIII. Officers and Employees ... 198 1. Status of Officers and Employees ... 198 2. Officer Compensation ... 200 IX. Affiliated Companies ... 201 X. Transactions with Major Shareholders ... 201 XI. Other Matters for Investor Protection ... 202 1. Progress and Changes in Disclosed Contents ... 202 2. Contingent Liabilities ... 202 3. Sanctions and Related Matters ... 203 4. Major Matters After the Reporting Date ... 203 XII. Detailed Tables ... 204 1. Status of Consolidated Subsidiaries (Detail) ... 204 2. Status of Affiliated Companies (Detail) ... 204 3. Status of Investments in Other Corporations (Detail) ... 204 [Confirmation by Experts] ... 204 1. Confirmation by Experts ... 204 2. Relationship with Experts ... 204 [Confirmation by CEO, etc.] (Confirmation by CEO, etc. - image) I. Overview of the Company 1. Company Overview A. Overview of Consolidated Subsidiaries (1) Status of Consolidated Subsidiaries (Summary) (Unit: Companies) Category | No. of Consolidated Companies | Major Subsidiaries Listed: Beginning 2 / Increase - / Decrease - / End 2 / Major 2 Unlisted: Beginning 8 / Increase - / Decrease - / End 8 / Major 1 Total: Beginning 10 / Increase - / Decrease - / End 10 / Major 3 * Refer to 'Detailed Table 1. Status of Consolidated Subsidiaries (Detail)' for details. (2) Changes in Consolidated Companies Newly Consolidated: None Excluded from Consolidation: None B. Legal and Commercial Name of the Company The Company's name is Daeduck Co., Ltd. Its English name is DAEDUCK CO., LTD., and its abbreviated form is (Co.) Daeduck. C. Date of Establishment The Company was established on August 11, 1972 with the manufacture and sale of PCBs (Printed Circuit Boards) as its main business purpose. On May 4, 2020 (the date of split registration), following a spin-off of the PCB business, the Company was converted into a holding company. D. Address, Phone Number, and Website of the Head Office Address: 230 Gangchon-ro, Danwon-gu, Ansan-si, Gyeonggi-do Phone: 031-8040-0823 Website: http://www.daeduckholdings.com E. SME, etc. Status SME Status: Not applicable Venture Company Status: Not applicable Mid-sized Company Status: Applicable F. Major Business Content The Company operates as a holding company, with its principal sources of revenue being dividend income from subsidiaries, management advisory fees, and trademark royalty income received from users of the 'Daeduck' brand, which the Company owns. The major businesses operated by its principal subsidiaries and affiliates include the manufacture and sale of PCBs, as well as the manufacture and sale of SAW filters and RF modules. For details, please refer to 'II. Business Content' of this disclosure document. G. Credit Rating Matters - Not applicable - H. Stock Listing (or Registration/Designation) and Special Listing Listing Status: Listed on the Securities Market Listing Date: January 26, 1989 Special Listing Type: Not applicable 2. Corporate History - Pursuant to the corporate disclosure form preparation standards, this item is not included in the quarterly report. (To be included in the semi-annual/annual report.) 3. Changes in Capital - Pursuant to the corporate disclosure form preparation standards, this item is not included in the quarterly report. (To be included in the semi-annual/annual report.) 4. Total Number of Shares - Pursuant to the corporate disclosure form preparation standards, this item is not included in the quarterly report... [Translation truncated]