This week's KOSPI gain was built in the first two sessions and partly erased in the last two. The gains were +4.61% on September 7 and +1.40% on September 9; the giveback was -0.25% on September 10 and -1.76% on September 11. Monday's rise traced to expectations for AI semiconductor demand. US markets were shut for Labor Day, only Korea traded, and Nvidia's Hugging Face acquisition and OpenAI's new model launch from the previous week fed expectations of stronger memory demand. Foreign investors bought a net 2.5532 trillion won and institutions 2.6491 trillion won. The declines on Thursday and Friday traced to oil and rates. West Texas Intermediate closed above 100 dollars at 102.48 on September 10 and the US 10-year yield reached 4.94%. US August core consumer prices, released on Friday, rose 0.3% on the month, 0.1 percentage point above forecast. Across the week other corporations bought more than 1.6 trillion won on every one of the five sessions, 8.4906 trillion won in total, while foreign investors sold a net 2.1701 trillion won. For the week KOSPI rose 3.33% and all three major US averages fell.