ASE Group Subsidiary REAL TECH HOLDINGS Announces Board Resolution to Acquire Equity Stake

1. Name and nature of the target (if preferred shares, specify issuance terms such as dividend rate): 100% equity interest in USI Asteelflash USA Corp.

2. Date on which the fact occurred: August 14, 2026 ~ August 14, 2026

3. Date of board approval: August 14, 2026

4. Other approval dates: Not applicable

5. Transaction quantity, unit price, and total transaction amount: Number of units and unit price: Not applicable Total transaction amount: USD 15,000,000.00

6. Counterparty and its relationship with the company (if the counterparty is an individual and not a related party, name disclosure may be omitted): USI Asteelflash USA Corp. is an affiliated company under the same group as REAL TECH HOLDINGS LIMITED.

7. If the counterparty is a related party, state the reason for selecting such party, previous transferor, relationship among previous transferor, company, and counterparty, transfer date, and amount: Reason for selecting related party: This transaction is a cash capital increase into a newly established subsidiary. Previous transferor, relationship among previous transferor, company, and counterparty, transfer date, and amount: Not applicable

8. If the target’s owner within the past five years was a related party of the company, disclose the related party’s acquisition and disposal date, price, and relationship with the company at the time: Not applicable

9. Matters related to the disposal of receivables (including types of collateral attached to disposed receivables; if receivables from related parties are involved, disclose the name and book value of such receivables): Not applicable

10. Gain (or loss) from disposal (not applicable for acquisition of securities) (if previously deferred, provide a table showing recognition status): Not applicable

11. Delivery or payment terms (including payment schedule and amounts), contractual restrictions, and other important agreements: Delivery or payment terms: Wire transfer; capital injection may be made in a single or multiple installments based on operational needs. Contractual restrictions and other important agreements: None

12. Decision-making method for the transaction, basis for price determination, and decision-making body: Approved by the board resolution of REAL TECH HOLDINGS LIMITED

13. Net asset value per share of the securities-issuing company acquired or disposed: Not applicable

14. Cumulative holdings (including this transaction) of the securities as of date, including quantity, amount, ownership percentage, and any restrictions on rights (e.g., pledge status): Amount: USD 15,000,000.00 Ownership percentage: 100% Rights restriction status: None

15. Proportion of securities investments (including this transaction) under Article 3 of the “Asset Acquisition and Disposal Rules for Publicly Issued Companies” to the company’s total assets and equity attributable to owners of the parent in the latest financial statements, and the amount of working capital in the latest financial statements: Percentage of total assets in latest financial statements: 19.18% Percentage of shareholders’ equity in latest financial statements: 20.73% Working capital in latest financial statements: NT$ -3,568,201 thousand

16. Broker and brokerage fees: None

17. Specific purpose or use of the acquisition or disposal of securities: Long-term investment

18. Dissenting opinions from directors regarding this transaction: None

19. Whether this transaction is a related-party transaction: Yes

20. Date of auditor’s acknowledgment or audit committee approval: Not applicable

21. Whether the accountant issued a non-reasonableness opinion on this transaction: Not applicable

22. Name of accounting firm: Not applicable

23. Name of accountant: Not applicable

24. Accountant’s license number: Not applicable

25. Whether this involves a change in business model: No

26. Explanation of business model change: Not applicable

27. Transaction history with the counterparty in the past year and expected in the next year: Not applicable

28. Source of funds: Not applicable

29. Previous date of material information disclosure on the same event: Not applicable

30. Other explanatory matters: None