CEO Lee Sang-ryul Buys 39,720 Shares on Open Market

Report on Ownership Status of Specified Securities by Executives and Major Shareholders 6.1 Cheonbo Co., Ltd. 2026-06-19 Report on Ownership Status of Specified Securities by Executives and Major Shareholders To: Securities and Futures Commission To: Korea Exchange Date of Reporting Obligation: June 19, 2026 Report Reference Date: June 19, 2026 * The reporter confirms that, as of the reference date, the ownership status of specified securities has been accurately prepared in accordance with relevant laws and disclosure rules, and that there is no false statement or omission of material matters. Reporter: Lee Sang-ryul 1. Information on the Issuer Company Name: Cheonbo Co., Ltd. Corporate Classification: KOSDAQ-listed corporation Company Code: 278280 Total Issued Shares: 12,253,025 2. Information on the Reporter Report Classification: Change Reporter Classification: Individual (Domestic) Name (Korean): Lee Sang-ryul Name (Chinese/English): 李相律 / LEE SANG RYUL Date of Birth: 1961-10-21 Address: Jungangtap-myeon, Chungju-si, Chungcheongbuk-do Relationship with Issuer: Executive (Registered) Position: CEO (Representative Director) Appointment Date: October 8, 2007 Resignation Date: - Major Shareholder: 10%+ shareholder Contact: Yoon Hong-hwan, Deputy General Manager, Management Team, Cheonbo Co., Ltd. Phone: 070-48******* Fax: 043-84****** Email: ******1@chunbochem.com 3. Ownership of Specified Securities A. Number and Ratio of Specified Securities Owned - Previous Report (2024-11-20): 4,258,244 specified securities (34.35%); 3,300,000 shares (33.00%) - This Report (2026-06-19): 4,297,964 specified securities (29.34%); 3,339,720 shares (27.26%) - Change: +39,720 specified securities (-5.01%p); +39,720 shares (-5.74%p) B. Holdings by Type of Specified Securities - Common stock (A): 3,339,720 - Warrants (B): - - Convertible bonds (C): - - Bonds with warrants (D): 958,244 - Profit-participating bonds (E): - - Exchangeable bonds (F): - - Depositary receipts (G): - - Other (H): - - Total (I): 4,297,964 (29.34%) - Total issued shares (J): 12,253,025 - Non-equity specified securities (B+C+D+E+F+G+H = I): 958,244 - Ownership ratio of specified securities [(A+I)/(J+I-(F+G+H))] x 100 = 29.34% - Ownership ratio of common stock (A/J) x 100 = 27.26% C. Detailed Change History All transactions dated June 19, 2026, on-market purchases (+) of common stock, prices ranging KRW 42,500-43,700: - 10 shares @ 42,550 (3,300,000 -> 3,300,010) - 3 shares @ 42,700 (3,300,010 -> 3,300,013) - 18 shares @ 42,650 (3,300,013 -> 3,300,031) - 1 share @ 42,550 (3,300,031 -> 3,300,032) - 193 shares @ 42,550 (3,300,032 -> 3,300,225) - 6 shares @ 42,500 (3,300,225 -> 3,300,231) - 218 shares @ 43,700 (3,300,231 -> 3,300,449) - 2 shares @ 43,650 (3,300,449 -> 3,300,451) - 3 shares @ 43,600 (3,300,451 -> 3,300,454) - 2 shares @ 43,550 (3,300,454 -> 3,300,456) - 1 share @ 43,550 (3,300,456 -> 3,300,457) - 4 shares @ 43,500 (3,300,457 -> 3,300,461) - 5 shares @ 43,600 (3,300,461 -> 3,300,466) - 1 share @ 43,600 (3,300,466 -> 3,300,467) - 2 shares @ 43,500 (3,300,467 -> 3,300,469) - 36 shares @ 43,600 (3,300,469 -> 3,300,505) - 1 share @ 43,600 (3,300,505 -> 3,300,506) - 1 share @ 43,600 (3,300,506 -> 3,300,507) - 83 shares @ 43,550 (3,300,507 -> 3,300,590) - 2 shares @ 43,600 (3,300,590 -> 3,300,592) - 21 shares @ 43,550 (3,300,592 -> 3,300,613) - 64 shares @ 43,500 (3,300,613 -> 3,300,677) - 1 share @ 43,550 (3,300,677 -> 3,300,678) - 173 shares @ 43,650 (3,300,678 -> 3,300,851) - 5 shares @ 43,550 (3,300,851 -> 3,300,856) - 2 shares @ 43,550 (3,300,856 -> 3,300,858) - 11 shares @ 43,350 (3,300,858 -> 3,300,869) - 16 shares @ 43,350 (3,300,869 -> 3,300,885) - 1 share @ 42,900 (3,300,885 -> 3,300,886) - 12 shares @ 42,950 (3,300,886 -> 3,300,898) - 2 shares @ 43,000 (3,300,898 -> 3,300,900) - 7 shares @ 43,000 (3,300,900 -> 3,300,907) - 11 shares @ 43,000 (3,300,907 -> 3,300,918) - 1 share @ 43,000 (3,300,918 -> 3,300,919) - 22 shares @ 43,000 (3,300,919 -> 3,300,941) - 14 shares @ 42,900 (3,300,941 -> 3,300,955) - 16 shares @ 42,900 (3,300,955 -> 3,300,971) - 8 shares @ 42,850 (3,300,971 -> 3,300,979) - 8 shares @ 42,900 (3,300,979 -> 3,300,987) - 18 shares @ 42,900 (3,300,987 -> 3,301,005) - 9 shares @ 42,900 (3,301,005 -> 3,301,014) - 6 shares @ ~42,7... [Translation truncated]