Our primary market risk exposures are to fluctuations in exchange rates, interest rates and fuel prices. We are exposed to foreign exchange risk related to foreign currency-denominated liabilities. As of December 31, 2025, 16.9% of our long-term debt (including the current portion but excluding original issue discounts and premium), without taking into consideration of swap transactions, was denominated in foreign currencies, principally U.S. dollar. However, a substantial portion of our revenues is denominated in Won. As a result, changes in exchange rates, particularly between the Won and the U.S. dollar, significantly affect us due to our significant amounts of foreign currency-denominated debt and the effect of such changes on the amount of funds required by us to make interest and principal payments on such debt. In order to reduce the impact of foreign exchange rate fluctuations on our results of operations, we have entered into currency swaps and other hedging arrangements with respect to our foreign currency denominated debt. We are also exposed to foreign exchange risk related to our purchases of fuel since we obtain substantially all of our fuel materials (other than anthracite coal) directly or indirectly from sources outside Korea. Prices for 163 Table of Contents such fuel materials are quoted based on prices stated in, and in many cases are paid for in, currencies other than Won. In 2025, fuel costs represented 20.1% of our sales. We are exposed to interest rate risk due to significant amounts of debt. Upward fluctuations in interest rates increase the cost of additional debt and the interest cost of outstanding floating rate borrowings. We are also exposed to fluctuations in prices of fuel materials. In 2025, for electricity generation, uranium accounted for 48.7% of our fuel requirements, coal accounted for 37.4%, LNG accounted for 9.9%, oil accounted for 0.1%, and others accounted for 3.9%, measured in each case by the amount of electricity we generated. In 2024, for electricity generation, uranium accounted for 48.1% of our fuel requirements, coal accounted for 35.9%, LNG accounted for 11.9%, oil accounted for 0.0%, and others accounted for 4.1%, measured in each case by the amount of electricity we generated. For additional discussions of our market risks, see Item 3.D. “Risk Factors” and Item 5.B. “Liquidity and Capital Resources—Liquidity.” We have entered into various swap contracts to hedge exchange rate risks arising from foreign currency-denominated debts. Details of currency swap contracts outstanding as of December 31, 2025 are as follows: Contract amount Contract interest rate Contract exchange rate (in won) Counterparty Contract year Pay Receive Pay Receive (In millions of won and thousands of foreign currencies except contract exchange rate information) <Trading> Standard Chartered 2014~2029 102,470 USD 100,000 3.14 % 3.57 % 1,024.70 Woori Bank 2019~2027 21,708 USD 19,417 5.04 % 6.75 % 1,118.00 Kookmin Bank 2020~2026 76,355 USD 70,445 5.83 % 6.00 % 1,083.90 Woori Bank 2021~2026 118,170 USD 100,000 1.11 % 1.13 % 1,181.70 Korea Development Bank 2021~2026 118,170 USD 100,000 1.11 % 1.13 % 1,181.70 Hana Bank 2021~2026 118,170 USD 100,000 1.11 % 1.13 % 1,181.70 JP Morgan 2022~2027 128,600 USD 100,000 3.56 % 4.00 % 1,286.00 Woori Bank 2022~2027 128,600 USD 100,000 3.56 % 4.00 % 1,286.00 Kookmin Bank 2022~2027 128,600 USD 100,000 3.56 % 4.00 % 1,286.00 Korea Development Bank 2022~2026 283,820 USD 200,000 4.67 % 5.38 % 1,419.10 Hana Bank 2022~2026 141,910 USD 100,000 4.68 % 5.38 % 1,419.10 Woori Bank 2022~2026 141,910 USD 100,000 4.68 % 5.38 % 1,419.10 JP Morgan 2022~2026 141,910 USD 100,000 4.69 % 5.38 % 1,419.10 Korea Development Bank 2022~2028 283,820 USD 200,000 5.12 % 5.50 % 1,419.10 Woori Bank 2022~2028 141,910 USD 100,000 5.13 % 5.50 % 1,419.10 Hana Bank 2023~2026 256,000 USD 200,000 3.97 % 5.38 % 1,280.00 Shinhan Bank 2023~2026 192,000 USD 150,000 3.99 % 5.38 % 1,280.00 Kookmin Bank 2023~2026 128,000 USD 100,000 4.03 % 5.38 % 1,280.00 Korea Development Bank 2023~2026 256,000 USD 200,000 4.04 % 5.38 % 1,280.00 Bank of America 2023~2026 128,000 USD 100,000 4.04 % 5.38 % 1,280.00 Standard Chartered 2023~2026 128,000 USD 100,000 4.04 % 5.38 % 1,280.00 Woori Bank 2023~2026 192,000 USD 150,000 4.05 % 5.38 % 1,280.00 Shinhan Bank 2024~2027 133,060 USD 100,000 3.53 % 4.88 % 1,330.60 Kookmin Bank 2024~2027 133,060 USD 100,000 3.53 % 4.88 % 1,330.60 Korea Development Bank 2024~2027 864,890 USD 650,000 3.53 % 4.88 % 1,330.60 Bank of America 2024~2027 133,060 USD 100,000 3.53 % 4.88 % 1,330.60 Standard Chartered 2024~2027 133,060 USD 100,000 3.53 % 4.88 % 1,330.60 IBK Securities Co., Ltd. 2024~2027 199,590 USD 150,000 3.53 % 4.88 % 1,330.60 Shinhan Bank 2024~2034 138,010 USD 100,000 3.64 % 5.13 % 1,380.10 Hana Bank 2024~2034 138,010 USD 100,000 3.69 % 5.13 % 1,380.10 Woori Bank 2024~2034 119,958 USD 86,920 3.74 % 5.13 % 1,380.10 Shinhan Bank 2025~2030 146,320 USD 100,000 3.18 % 4.13 % 1,463.20 Hana Bank 2025~2030 438,960 USD 300,000 3.21 % 4.13 % 1,463.20 Kookmin Bank 2025~2028 292,640 USD 200,000 2.99 % SOFR + 0.62 % 1,463.20 Bank of America 2025~2028 219,480 USD 150,000 2.99 % SOFR + 0.62 % 1,463.20 Hana Bank 2025~2028 146,320 USD 100,000 3.00 % SOFR + 0.62 % 1,463.20 Korea Development Bank 2025~2028 73,160 USD 50,000 3.02 % SOFR + 0.62 % 1,463.20 164 Table of Contents Contract amount Contract interest rate Contract exchange rate (in won) Counterparty Contract year Pay Receive Pay Receive Shinhan Bank 2025~2028 146,320 USD 100,000 3.02 % SOFR + 0.62 % 1,463.20 Woori Bank 2017~2027 111,610 USD 100,000 2.25 % 3.13 % 1,116.10 Korea Development Bank 2017~2027 111,610 USD 100,000 2.31 % 3.13 % 1,116.10 Hana Bank 2017~2027 111,610 USD 100,000 2.31 % 3.13 % 1,116.10 Korea Development Bank 2018~2028 108,600 HKD 800,000 2.69 % 3.35 % 135.75 Shinhan Bank 2018~2028 115,388 HKD 850,000 2.66 % 3.35 % 135.75 Korea Development Bank 2019~2027 119,978 CHF 100,000 1.43 % 0.05 % 1,199.78 Woori Bank 2021~2026 222,800 USD 200,000 0.93 % 1.25 % 1,114.00 Shinhan Bank 2021~2026 111,400 USD 100,000 0.92 % 1.25 % 1,114.00 Korea Development Bank 2021~2026 111,399 USD 100,000 0.93 % 1.25 % 1,114.00 Nonghyup Bank 2021~2026 111,400 USD 100,000 0.93 % 1.25 % 1,114.00 Woori Bank 2022~2027 262,000 USD 200,000 3.62 % 4.25 % 1,310.00 Export-Import Bank of Korea 2022~2027 131,000 USD 100,000 3.63 % 4.25 % 1,310.00 Kookmin Bank 2022~2027 131,000 USD 100,000 3.62 % 4.25 % 1,310.00 Hana Bank 2022~2027 131,000 USD 100,000 3.61 % 4.25 % 1,310.00 Korea Development Bank 2022~2027 262,000 USD 200,000 3.63 % 4.25 % 1,310.00 Export-Import Bank of Korea 2022~2032 349,829 HKD 1,935,000 4.87 % 5.16 % 180.79 JP Morgan 2022~2032 75,194 HKD 415,000 5.00 % 5.16 % 181.19 Export-Import Bank of Korea 2023~2030 172,982 HKD 1,037,000 4.25 % 4.51 % 166.81 Hana Bank 2024~2028 128,940 USD 100,000 3.73 % 5.00 % 1,289.40 JP Morgan 2024~2028 128,940 USD 100,000 3.85 % 5.00 % 1,289.40 Korea Development Bank 2024~2028 257,880 USD 200,000 3.80 % 5.00 % 1,289.40 Korea Development Bank 2024~2028 128,940 USD 100,000 3.69 % 5.00 % 1,289.40 Hana Bank 2024~2029 138,540 USD 100,000 3.15 % 4.63 % 1,385.40 Shinhan Bank 2024~2029 138,540 USD 100,000 3.15 % 4.63 % 1,385.40 Kookmin Bank 2024~2029 138,540 USD 100,000 3.16 % 4.63 % 1,385.40 Woori Bank 2024~2029 138,540 USD 100,000 3.17 % 4.63 % 1,385.40 Korea Development Bank 2024~2029 138,540 USD 100,000 3.19 % 4.63 % 1,385.40 Credit Agricole 2025~2028 218,963 HKD 1,166,000 2.85 % 4.10 % 187.79 Korea Development Bank 2025~2030 556,560 USD 400,000 2.75 % SOFR + 0.79 % 1,391.40 Hana Bank 2025~2030 139,140 USD 100,000 2.75 % SOFR + 0.79 % 1,391.40 <Cash flow hedge> Korea Development Bank 2020~2026 118,910 USD 100,000 0.61 % 1.00 % 1,189.10 Hana Bank 2020~2026 118,910 USD 100,000 0.61 % 1.00 % 1,189.10 Woori Bank 2020~2026 118,910 USD 100,000 0.62 % 1.00 % 1,189.10 Nomura 2017~2037 52,457 EUR 40,000 2.60 % 1.70 % 1,311.42 Nomura 2017~2037 59,423 SEK 450,000 2.62 % 2.36 % 132.05 Kookmin Bank 2021~2026 114,230 USD 100,000 1.27 % 1.25 % 1,142.30 Korea Development Bank 2021~2026 114,230 USD 100,000 1.27 % 1.25 % 1,142.30 Hana Bank 2021~2026 114,230 USD 100,000 1.27 % 1.25 % 1,142.30 Korea Development Bank 2022~2027 123,710 USD 100,000 3.41 % 3.63 % 1,237.10 Woori Bank 2022~2027 123,710 USD 100,000 3.41 % 3.63 % 1,237.10 JP Morgan 2022~2027 123,710 USD 100,000 3.41 % 3.63 % 1,237.10 Woori Bank 2021~2026 220,600 USD 200,000 0.47 % 0.75 % 1,103.00 Shinhan Bank 2021~2026 220,600 USD 200,000 0.47 % 0.75 % 1,103.00 Hana Bank 2021~2026 55,150 USD 50,000 0.48 % 0.75 % 1,103.00 Shinhan Bank 2023~2026 132,930 USD 100,000 4.07 % 5.38 % 1,329.30 Nonghyup Bank 2023~2026 132,930 USD 100,000 4.05 % 5.38 % 1,329.30 Kookmin Bank 2023~2026 132,930 USD 100,000 4.07 % 5.38 % 1,329.30 Woori Bank 2023~2028 259,000 USD 200,000 3.83 % 4.88 % 1,295.00 Korea Development Bank 2023~2028 129,500 USD 100,000 3.85 % 4.88 % 1,295.00 Bank of America 2023~2028 64,750 USD 50,000 3.85 % 4.88 % 1,295.00 Woori Bank 2025~2031 142,900 USD 100,000 2.93 % 4.00 % 1,429.00 Hana Bank 2025~2031 142,900 USD 100,000 2.93 % 4.00 % 1,429.00 Shinhan Bank 2025~2031 71,450 USD 50,000 2.94 % 4.00 % 1,429.00 Bank of America 2025~2031 71,450 USD 50,000 2.94 % 4.00 % 1,429.00 Under these currency swap contracts, we recognized net valuation gain of Won 26 billion in 2025. 165 Table of Contents Details of interest rate contracts outstanding as of December 31, 2025 are as follows: In millions of won and thousands of foreign currencies Counterparty Contract year Contract Amount Contract interest rate per annum Pay Receive <Trading> Nomura (*1) 2018~2038 W 30,000 3M CD + 0.10% 3.75% Hana Bank 2022~2027 200,000 3.02% 3M CD + 0.61% Hana Bank 2022~2027 200,000 3.04% 3M CD + 0.58% Hana Bank 2022~2027 250,000 3.38% 3M CD + 0.59% Nomura 2022~2027 200,000 3.55% 3M CD + 0.60% Shinhan Bank 2022~2027 150,000 3.53% 3M CD + 0.55% Hana Bank 2022~2027 200,000 3.70% 3M CD + 0.59% Nomura 2022~2027 300,000 3.89% 3M CD + 0.67% Hana Bank 2022~2027 200,000 3.93% 3M CD + 0.67% Nomura 2022~2027 200,000 3.80% 3M CD + 0.68% Nomura 2022~2027 300,000 4.04% 3M CD + 0.60% Hana Bank 2022~2027 100,000 4.68% 3M CD + 1.04% Hana Bank 2022~2027 100,000 5.45% 3M CD + 1.20% Shinhan Bank 2023~2028 200,000 4.27% 3M CD + 0.76% Shinhan Bank 2023~2028 50,000 4.27% 3M CD + 0.76% Nomura 2023~2028 250,000 4.13% 3M CD + 0.73% Hana Bank 2023~2028 200,000 3.74% 3M CD + 0.51% Hana Bank 2023~2028 100,000 4.19% 3M CD + 0.50% Shinhan Bank 2023~2028 300,000 3.81% 3M CD + 0.70% Hana Bank 2023~2028 200,000 3.95% 3M CD + 0.50% Shinhan Bank 2024~2029 200,000 3.84% 3M CD + 0.50% Hana Bank 2024~2027 250,000 3.72% 3M CD + 0.34% Hana Bank 2024~2027 250,000 3.77% 3M CD + 0.31% Hana Bank 2024~2027 250,000 3.31% 3M CD + 0.31% Hana Bank 2024~2027 200,000 3.46% 3M CD + 0.53% Nomura 2024~2027 200,000 3.38% 3M CD + 0.50% Hana Bank 2024~2027 300,000 3.18% 3M CD + 0.53% Hana Bank 2025~2030 200,000 3.28% 3M CD + 0.57% Hana Bank 2025~2030 200,000 3.28% 3M CD + 0.62% Shinhan Bank 2025~2030 200,000 2.82% 3M CD + 0.50% Hana Bank 2025~2028 200,000 2.86% 3M CD + 0.45% Hana Bank 2025~2028 200,000 2.85% 3M CD + 0.25% Shinhan Bank 2025~2026 100,000 3.30% 3M CD + 0.45% Nomura 2017~2032 52,457 Floating rate + 2.55% 2.60% Nomura 2017~2032 59,423 Floating rate + 2.57% 2.62% Nomura (*2) 2021~2041 30,000 1.84% 2.60% Nomura (*3) 2021~2041 50,000 1.87% 2.38% MUFG 2022~2048 USD 155,941 3M SOFR 3.71% Mizuho Capital Markets LLC 2022~2048 USD 155,941 3M SOFR 1.05% NORD LB Bank 2022~2036 USD 16,121 1.83% 6M SOFR Rabobank 2022~2036 USD 19,619 1.83% 6M SOFR Mizuho Capital Markets LLC 2024~2045 USD 77,399 3M USD Synthetic Libor 1.14% <Cash flow hedge> Export-Import Bank of Korea 2015~2031 USD 11,021 2.67% SOFR + 0.43% ING Bank 2015~2031 USD 27,178 2.67% SOFR + 0.43% BNP Paribas 2015~2031 USD 28,994 2.67% SOFR + 0.43% BNP Paribas 2009~2027 USD 22,923 4.16% 6M USD Synthetic Libor KFW 2009~2027 USD 22,923 4.16% 6M USD Synthetic Libor Export-Import Bank of Korea 2016~2036 USD 51,095 3.00% 6M USD Synthetic Libor SMTB 2025~2036 JPY 3,557,580 1.82% 6M TIBOR + 0.55% Notes: (1) Depending on the counterparty exercising the right, the contract may be early settled on the same date every year from June 15, 2023. 166 Table of Contents (2) 1.84% of the contract paying interest rate is applied for five years from the date of issuance, and 3M CMT+0.35% is applied thereafter. (3) 1.87% of the contract paying interest rate is applied for five years from the date of issuance, and 3M CMT+0.35% is applied thereafter. Under these interest rate swap contracts, we recognized net valuation gain of Won 45 billion in 2025. We engage in transactions denominated in foreign currencies and consequently become exposed to fluctuations in exchange rates. The carrying amounts of our foreign currency-denominated monetary assets and monetary liabilities as of December 31, 2024 and 2025 were as follows: Assets Liabilities Type 2025 2024 2025 2024 In thousands of foreign currencies AED 51,617 33,465 4,927 8,795 AUD 49 26 — 64 BDT 2,251 2,252 — — BWP 726 768 — — EGP 759,561 203,044 — — CAD 579 2 — 61 CHF — — 99,946 100,686 DOP 6,378 7,772 — — EUR 89,734 20,433 44,482 47,829 GBP 90 139 — 4 HKD — — 6,286,899 5,093,862 IDR 37,788,922 37,830,902 49,014,235 4,027,099 INR 1,175,785 1,037,437 161,578 225,042 JOD 646 902 433 49,128 JPY 60,443 23,798 746,066 7,483,199 KZT 1,485 1,510 — — MGA 7,038,637 5,452,745 577,908 248,175 MMK 188,021 188,021 — — MYR 2,805 2,805 — — PHP 71,400 19,401 — — PKR 64,839,210 68,734,242 10,418 10,418 RON 748 — — — SAR 1,069 1,087 — — SEK — — 449,349 449,302 SGD 1,783 291 — 110 USD 1,356,230 1,651,765 13,851,077 15,364,685 UYU 93,414 99,189 1,285 1,141 VND 772,198 733,338 — 587,003 ZAR 84,167 79,897 — — The following analysis sets forth the sensitivity of our consolidated net income before income taxes (our “pre-tax income”) to changes in exchange rates, interest rates, electricity rates and fuel costs. For purposes of this section, we and our related parties are deemed one entity. The range of changes in such risk categories represents our view of the changes that are reasonably possible over a one-year period, although it is difficult to predict such changes as a result of adverse economic developments in Korea. See Item 3.D. “Risk Factors—Risks Relating to Korea and the Global Economy—Unfavorable financial and economic conditions in Korea and globally may have a material adverse impact on us.” The following discussion only addresses material market risks faced by us and does not discuss other risks which we face in the normal course of business, including country risk, credit risk and legal risk. Unless otherwise specified, all calculations are made under IFRS. 167 Table of Contents If the Won depreciates against the U.S. dollar and all other foreign currencies held by us by 10%, and all other variables are held constant from their levels as of December 31, 2025, we estimate that our unrealized foreign exchange translation losses will increase by Won 1,885 billion in 2025. Such sensitivity analysis is conducted for monetary assets and liabilities denominated in foreign currencies other than functional currency as of December 31, 2024 and 2025, without taking into consideration of the hedge effect of swap transactions. To manage our foreign currency risk related to foreign currency-denominated receivables and payables, we have a policy of entering into currency forward agreements. In addition, to manage our foreign currency risk related to foreign currency-denominated expected sales transactions and purchase transactions, we enter into cross-currency swap agreements. We are exposed to interest rate risk due to our borrowings with floating interest rates. If interest rates increase by 1% on all of our borrowings and debentures bearing variable interest, and all other variables are held constant as of December 31, 2025, we estimate that our profit before income taxes will decrease by Won 152 billion (not reflecting the fact that a portion of such interest may be capitalized under IFRS) in 2025. Such sensitivity analysis does not take into consideration of the hedge effect of interest rate swap transactions. To manage our interest rate risks, we, in addition to maintaining an appropriate mix of fixed and floating rate loans, have entered into certain interest rate swap agreements. We are exposed to electricity rates risk due to the rate regulation by the Government, which considers the effect of electricity rate changes on the national economy. If the electricity rate rises by 1% and all other variables are held constant as of December 31, 2025, we estimate that our profit before income taxes will increase by Won 930 billion in 2025. We are exposed to fuel price risks due to the heavy influence of fuel costs on our sales and cost of sales. If the fuel prices of anthracite and bituminous coal, oil, LNG and others used for generation by us and our generation subsidiaries rise by 1% and all other variables are held constant as of December 31, 2025, we estimate that our profit before income taxes will decrease by Won 191 billion in 2025. The above discussion and the estimated amounts generated from the sensitivity analyzes referred to above include “forward-looking statements,” which assume for analytical purposes that certain market conditions may occur. Accordingly, such forward-looking statements should not be considered projections by us of future events or losses. See Note 45 of the notes to our consolidated financial statements included in this annual report for further related information. ITEM 12. DESCRIPTION OF SECURITIES OTHER THAN EQUITY SECURITIES Item 12.A. Debt Securities Not applicable. Item 12.B. Warrants and Rights Not applicable. Item 12.C. Other Securities Not applicable.