Investors ranked in the top 1% by one-month investment returns among Mirae Asset Securities clients sold SK hynix, Samsung Electronics and Samsung Electro-Mechanics most heavily on the morning of the 10th. SK hynix was the largest net sale through 11 a.m., trading at 1.838 million won, down 0.97%, while its American depositary receipts rose more than 7% after U.S. stocks fell broadly overnight amid continuing Middle East geopolitical tension. Domestic shares opened higher before turning lower as caution increased on a quadruple witching day, when index futures, index options, single-stock futures and single-stock options expire together. Samsung Electronics fell 1.48% to 265,500 won, while Samsung Electro-Mechanics dropped 3.35% to 1.357 million won after a sharp rally prompted profit-taking. A day earlier, Samsung Electronics Chairman Jay Y. Lee bought about 1.9 trillion won of Samsung Electronics shares, representing a 0.11% stake, from Hong Ra-hee, honorary director of the Leeum Museum of Art. Brokerages continue to identify Samsung Electronics and SK hynix as key beneficiaries of artificial intelligence adoption. KB Securities said U.S. high-performance models are increasing computing and data-processing demand, while low-cost Chinese models are broadening AI users and usage frequency, supporting memory demand from both directions. With new supply limited, the brokerage expects a strong upcycle of rising memory prices and shipments to continue next year. Samsung Electro-Mechanics has benefited from a shortage of multilayer ceramic capacitors as AI server deployment expands, while market participants say its position is strengthening as Murata directs capacity toward higher-value AI-server products. The most heavily bought stocks were Hyundai Motor, Korea Electric Power and Celltrion. Mirae Asset's disclosed data covers top-return clients on a real-time, previous-day and five-day basis, is informational only, does not represent the brokerage's views and does not guarantee suitable investments or returns.