FORTUM CORPORATION STOCK EXCHANGE RELEASE 20 AUGUST 2025 AT 8:45 EEST Release category: Managers' transactions Person subject to the notification requirement Name: Lundström, Petra Position: Other senior manager Issuer: Fortum Corporation LEI: 635400IUIZZIUJSAMF76 Notification type: INITIAL NOTIFICATION Reference number: 635400IUIZZIUJSAMF76_20250819135251_358 Transaction date: 2025-08-18 Venue: XHEL Instrument type: SHARE ISIN: FI0009007132 Nature of the transaction: ACQUISITION Transaction details (1): Volume: 164 Unit price: 15.2256 EUR Aggregated transactions (1): Volume: 164 Volume weighted average price: 15.2256 EUR Fortum Corporation Further information: Ingela Ulfves, Vice President, Investor Relations and Financial Communications, tel. +358 40 5151 531 Distribution: Nasdaq Helsinki Main media www.fortum.com Fortum Fortum is a Nordic energy company. We generate and deliver reliable energy to our customers and the Nordic energy system while at the same time helping industries decarbonise their processes and grow. Our core operations comprise efficient and best-in-class low-carbon power generation, customer services, and heating and cooling. Fortum's power generation is already 99% from renewable or nuclear sources with one of the lowest specific CO2-emissions in Europe. We are guided by our ambitious SBTi-validated emission reduction targets on our way towards net-zero by 2040. For our ~4,500 employees, we commit to be a safe and inspiring workplace. Fortum's share is listed on Nasdaq Helsinki. fortum.com (https://www.fortum.com)