Announcement PDF RNS Number : 7165G Great Southern Copper PLC 02 June 2026 TR-1: Standard form for notification of major holdings 1. Issuer Details ISIN GB00BLB5BF24 Issuer Name GREAT SOUTHERN COPPER PLC UK or Non-UK Issuer UK 2. Reason for Notification An acquisition or disposal of voting rights; An acquisition or disposal of financial instruments; An event changing the breakdown of voting rights 3. Details of person subject to the notification obligation Name Spreadex LTD City of registered office (if applicable) St. Albans Country of registered office (if applicable) United Kingdom 4. Details of the shareholder Full name of shareholder(s) if different from the person(s) subject to the notification obligation, above City of registered office (if applicable) Country of registered office (if applicable) 5. Date on which the threshold was crossed or reached 01-Jun-2026 6. Date on which Issuer notified 02-Jun-2026 7. Total positions of person(s) subject to the notification obligation % of voting rights attached to shares (total of 8.A) % of voting rights through financial instruments (total of 8.B 1 + 8.B 2) Total of both in % (8.A + 8.B) Total number of voting rights held in issuer Resulting situation on the date on which threshold was crossed or reached 1.935700 1.735600 3.671300 28259999 Position of previous notification (if applicable) 1.357900 1.262600 2.620500 8. Notified details of the resulting situation on the date on which the threshold was crossed or reached 8A. Voting rights attached to shares Class/Type of shares ISIN code(if possible) Number of direct voting rights (DTR5.1) Number of indirect voting rights (DTR5.2.1) % of direct voting rights (DTR5.1) % of indirect voting rights (DTR5.2.1) GB00BLB5BF24 14899999 1.935700 Sub Total 8.A 14899999 1.935700% 8B1. Financial Instruments according to (DTR5.3.1R.(1) (a)) Type of financial instrument Expiration date Exercise/conversion period Number of voting rights that may be acquired if the instrument is exercised/converted % of voting rights CFD/Spreadbet 13360000 1.735600 Sub Total 8.B1 13360000 1.735600% 8B2. Financial Instruments with similar economic effect according to (DTR5.3.1R.(1) (b)) Type of financial instrument Expiration date Exercise/conversion period Physical or cash settlement Number of voting rights % of voting rights Sub Total 8.B2 9. Information in relation to the person subject to the notification obligation 1. Person subject to the notification obligation is not controlled by any natural person or legal entity and does not control any other undertaking(s) holding directly or indirectly an interest in the (underlying) issuer. Ultimate controlling person Name of controlled undertaking % of voting rights if it equals or is higher than the notifiable threshold % of voting rights through financial instruments if it equals or is higher than the notifiable threshold Total of both if it equals or is higher than the notifiable threshold 10. In case of proxy voting Name of the proxy holder The number and % of voting rights held The date until which the voting rights will be held 11. Additional Information Matthew Allen Joanna Diep 01727895011 01727895122 Additionally please add: Spreadex is an FCA regulated provider of spread betting and CFD trading. Founded in 1999, Spreadex gives both retail and professional traders the opportunity to trade over 10,000 global markets, including UK small caps. For more information see www.spreadex.com/financials. 12. Date of Completion 02-Jun-2026 13. Place Of Completion UK This information is provided by RNS, the news service of the London Stock Exchange. RNS is approved by the Financial Conduct Authority to act as a Primary Information Provider in the United Kingdom. Terms and conditions relating to the use and distribution of this information may apply. For further information, please contact rns@lseg.com or visit www.rns.com. RNS may use your IP address to confirm compliance with the terms and conditions, to analyse how you engage with the information contained in this communication, and to share such analysis on an anonymised basis with others as part of our commercial services. For further information about how RNS and the London Stock Exchange use the personal data you provide us, please see our Privacy Policy. END HOLAKBBNPBKDAAK