Material event report (treasury share acquisition) (subsidiary)

What happened

Material event report / Matter subject to KRX reporting obligation Report on a material management matter of subsidiary SK hynix Inc. To: Financial Services Commission / Korea Exchange August 19, 2026 Company name: SK hynix Inc. CEO: Kwak No-jung Head office location: 2091 Gyeongchung-daero, Bubal-eup, Icheon-si, Gyeonggi-do Phone: 031-5185-4114 Website: http://www.skhynix.com Preparer: (Title) Head of Finance Division (Name) Kim Woo-hyun (Phone) 031-5185-4114

Decision on treasury share acquisition 1. Planned shares to be acquired (shares): common stock 24,070,000; other stock - 2. Planned acquisition amount (KRW): common stock 40,004,340,000,000; other stock - 3. Expected acquisition period: start August 20, 2026; end November 19, 2026 4. Expected holding period: start -; end - 5. Purpose of acquisition: Enhancing shareholder value through retirement of treasury shares 6. Acquisition method: On-market purchase 7. Entrusted investment broker: SK Securities Co., Ltd. 8. Treasury shares held before acquisition: within distributable profit range (shares): common stock 1,625,696; ratio (%) 0.2; other stock -; ratio -; other acquisition (shares): common stock 73; ratio (%) 0.0; other stock -; ratio - 9. Date of acquisition decision: August 19, 2026; attendance of independent (outside) directors*: attended 6, absent 0; attendance of auditor (audit committee member who is not an independent (outside) director*): - 10. Daily purchase order quantity limit: common stock 2,407,000; other stock - * Independent director for listed companies, outside director for unlisted companies 11. Other matters for investment reference: - This decision on treasury share acquisition is a new acquisition. - "1. Planned shares to be acquired" above was calculated from "2. Planned acquisition amount" using the closing price on the trading day before the board resolution date (as of August 18, 2026: KRW 1,662,000); the number of shares actually acquired may change with future share price movements. - "4. Expected holding period" above may vary with the Company's financial condition, market conditions and other circumstances. However, as this acquisition is intended for retirement, the Company plans to retire all treasury shares acquired within "3. Expected acquisition period" after completing the acquisition. Details of the retirement can be found in the Company's "Decision on share retirement" disclosure filed on August 19, 2026. - The treasury shares under "8. Treasury shares held before acquisition - other acquisition (common stock)" above arose from the Company's exercise, in May 2026, of the early redemption right (Clean-Up Call Option) on exchangeable bonds issued on April 11, 2023. - "9. Date of acquisition decision" above is the date of the board resolution. - The basis for "10. Daily purchase order quantity limit," under Article 5-5 of the Regulation on Issuance and Disclosure of Securities, etc., is the smaller of [the greater of ① and ②] and ③: ① 10% of shares reported for acquisition: 2,407,000 shares; ② 25% of average daily trading volume over the 1 month preceding the day before the board resolution date: 1,431,989 shares; ③ 1% of total shares issued: 7,304,923 shares

[Treasury share acquisition amount limit] Item | Amount 1. Limit based on distributable profit under the Commercial Act as of the end of the immediately preceding fiscal year a. Net assets: 117,318,562,193,943 b. Amount of capital stock: 3,657,652,050,000 c. Sum of capital reserves and earnings reserves accumulated through the end of the immediately preceding fiscal year: 9,867,146,544,188 d. Unrealized gains prescribed by Presidential Decree: 12,239,000,231,484 Subtotal (a-b-c-d): 91,554,763,368,271 2. Treasury shares acquired since the end of the immediately preceding fiscal year: - 3. Dividend amount resolved at the regular shareholders' meeting since the end of the immediately preceding fiscal year, and related earnings reserve: 1,538,579,052,713 4. Quarterly/interim dividend amount resolved by the board since the end of the immediately preceding fiscal year, and related earnings reserve: 593,975,016,113 5. Contract amount of trust contracts: - 6. Acquisition cost of treasury shares disposed of since the end of the immediately preceding fiscal year (moving average method): 25,802,387,418 Treasury share acquisition amount limit (1-2-3-4-5+6): 89,448,011,686,863 Note 1) "1." above is based on the fiscal year 2025 settlement. Note 2) Amounts above are in KRW.

[Treasury shares held before the treasury share acquisition decision] (Unit: shares) Acquisition method | Type | Beginning balance | Acquired(+) | Disposed(-) | Retired(-) | Ending balance | Note Within distributable profit range, direct acquisition, on-market: common stock 17,377,728 / - / 452,032 / 15,300,000 / 1,625,696 / -; other stock - / - / - / - / - / - Off-market direct acquisition: all - Tender offer: all - Subtotal (a): common stock 17,377,728 / - / 452,032 / 15,300,000 / 1,625,696; other stock - Trust-contract acquisition (trustee-held volume, in-kind held volume): all -; Subtotal (b): all - Other acquisition (c): common stock - / 73 / - / - / 73; other stock - Total (a+b+c): common stock 17,377,728 / 73 / 452,032 / 15,300,000 / 1,625,769; other stock - Note) In May 2026, the Company additionally acquired 73 treasury shares arising from odd-lot handling upon exercise of the early redemption right (Clean-Up Call Option) on exchangeable bonds issued on April 11, 2023. - "Beginning balance" above is the quantity of treasury shares held as of the start of the current fiscal year (January 1, 2026); "ending balance" is the quantity held as of the filing date of this disclosure (August 19, 2026).