Treasury share acquisition: results report

What happened

Cas Co., Ltd. Treasury share acquisition: results report To: Financial Supervisory Service August 19, 2026 Company name: Cas Co., Ltd. CEO: Kim Tae-in Head office location: 262 Geurugogae-ro, Gwangjeok-myeon, Yangju-si, Gyeonggi-do Phone: 031-820-1100 Website: http://www.cas.co.kr Preparer: (Title) Managing Director (Name) Jeon Jong-il (Phone) 02-2225-3648

1. Name and address of the issuer a. Name: Cas Co., Ltd. b. Address: 262 Geurugogae-ro, Gwangjeok-myeon, Yangju-si, Gyeonggi-do

2. Details of the acquisition report a. Material event report filing date: August 3, 2026 b. Acquisition period: from August 4, 2026 to August 18, 2026

3. Acquisition details (Unit: KRW, shares) Date 2026.08.04: Order quantity 49,652; Acquired quantity 46,955; Price per share 1,017; Total amount 47,762,289; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.05: Order quantity 49,652; Acquired quantity 49,652; Price per share 1,043; Total amount 51,763,013; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.06: Order quantity 49,652; Acquired quantity 49,652; Price per share 1,025; Total amount 50,892,720; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.07: Order quantity 49,652; Acquired quantity 49,652; Price per share 1,037; Total amount 51,497,555; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.10: Order quantity 49,652; Acquired quantity 49,652; Price per share 1,050; Total amount 52,111,162; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.11: Order quantity 49,652; Acquired quantity 48,239; Price per share 1,054; Total amount 50,839,035; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.12: Order quantity 49,652; Acquired quantity 49,568; Price per share 1,055; Total amount 52,281,198; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.13: Order quantity 49,652; Acquired quantity 39,652; Price per share 1,047; Total amount 41,515,057; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.14: Order quantity 49,652; Acquired quantity 49,652; Price per share 1,053; Total amount 52,305,834; Broker Shinhan Investment Corp.; ID 00138321 Date 2026.08.18: Order quantity 49,652; Acquired quantity 45,116; Price per share 1,087; Total amount 49,031,440; Broker Shinhan Investment Corp.; ID 00138321 Total: Order quantity 496,520; Acquired quantity 477,790; Average price per share 1,046; Total amount 499,999,303

4. Whether the planned and actual acquisition details match Planned acquisition amount (KRW): common stock 499,999,668; other stock - Total acquisition amount (KRW): common stock 499,999,303; other stock - Shortfall from planned amount: -; reason for shortfall, if any: - ※ The Company completed its share purchase as close as possible to the planned acquisition amount stated in the material event report; the difference between the total acquisition amounts is less than the price of one share. ※ Due to share price fluctuations during the acquisition period, a difference arose between the planned acquisition quantity (496,524 shares) and the actual acquisition quantity (477,790 shares).

5. Holding status of treasury shares after acquisition [as of August 19, 2026] (Unit: KRW, shares, %) Type: common stock; Holdings under Article 165-3 (A): quantity 3,370,314; ratio 13.11%; total value 4,115,546,287; Holdings under trust contract (B): -; Total (A+B): quantity 3,370,314; ratio 13.11%; amount 4,115,546,287

6. Change in largest shareholder's holdings before/after acquisition [as of August 19, 2026] (Unit: shares) Name: Kim Dong-jin; Common stock: shares as of acquisition report date 5,282,555; shares as of acquisition end date 5,282,555; reason for change - Total: common stock 5,282,555 / 5,282,555 / -; other stock - / - / -; Grand total 5,282,555 / 5,282,555 / -