Material event report (decision to redeem own convertible bonds early)

What happened

Material event report (decision to redeem own convertible bonds before maturity) 6.0 Atum Co., Ltd. Material event report / Korea Exchange disclosure obligation To: Financial Services Commission / Korea Exchange Date: August 27, 2026 Company name: Atum Co., Ltd. Representative director: Han Taek-su Head office: 6F, 603-2, 38-9 Digital-ro 31-gil, Guro-gu, Seoul (Tel) 02-2675-3020 (Website) http://www.iatum.com Preparer: (Title) Representative Director (Name) Han Taek-su (Tel) 02-2675-3020

Decision to redeem own convertible bonds before maturity

1. Type of bond: 2nd series, domestic unregistered interest-bearing unsecured privately placed convertible bonds 2. Bond issuance date: February 27, 2025 3. Issuance method: private placement 4. Bond maturity date: February 27, 2028 5. Total face value (book-entry) of the bond (KRW): 4,000,000,000 6. Face value (book-entry) of bonds to be acquired (KRW): 1,000,000,000 7. Acquisition decision date: August 27, 2026 8. Acquisition amount (KRW): 1,030,115,000; basis: principal and interest; payment (expected) date: August 27, 2026; source of acquisition funds: own funds 9. Acquisition method: over-the-counter purchase 10. Reason for acquisition before maturity: bondholder's exercise of a put option 11. Future handling plan: retirement after acquisition 12. Conversion matters: conversion ratio 100%; conversion price as of reporting date (KRW/share) 4,274; class of shares to be issued: Atum Co., Ltd. registered common shares; number of shares 233,972; ratio to total shares outstanding 2.39%; conversion request period: start February 27, 2026, end January 27, 2028 13. Remaining face value (book-entry) of the bond after acquisition (KRW): 700,001,216 14. Subject to Fair Trade Commission reporting: not applicable 15. Other material matters relevant to investment decisions: the acquisition amount above includes principal and interest; the acquisition decision date is the board resolution date, and the payment (expected) date is the early-redemption payment date.

[Seller particulars]: no entries disclosed (all fields -).