AI Memory Stocks Slide as U.S. Treasury Yields Spike

* Editor's note: AI PRISM (Personalized Report & Insight Summarizing Media) is an AI-based personalized news recommendation and summary service developed with support from the Korea Press Foundation. It selects and provides six tailored news items by reader type.

1. Has the AI Memory Supercycle Cracked? HBM Demand Holds, Yet Samsung and SK hynix Take a Hit

- Key summary: AI memory chip stocks fell across the board on the New York Stock Exchange on the 18th local time, and in the aftermath Samsung Electronics (005930.KS) and SK hynix dropped 7.82% and 9.75%, respectively, as of the closing price on the 19th. The Philadelphia Semiconductor Index plunged 4.98% to 11,992.46, and Micron Technology closed down 7.02% at $940.76. The direct cause cited was that the U.S. 30-year Treasury yield topped 5.33% intraday, its highest since 2007. Meanwhile, the market pointed to the possibility that rising memory prices could pressure returns on AI infrastructure investment, and to China's ChangXin Memory Technologies (CXMT) expanding capacity for commodity DRAM, as factors behind cracks in the supercycle.

2. SK hynix to Make Further Announcements Around October, Including Special Dividend; Shareholder Returns Seen Reaching 100 Trillion Won This Year

- Key summary: SK hynix decided through a board resolution on the 19th to acquire 40.0434 trillion won worth of its own shares and cancel them in full. The volume to be bought and cancelled amounts to 24.07 million common shares, or 3.3% of total issued shares, the largest share cancellation among Korean listed companies. The company also decided to expand the funds for shareholder returns from within 50% of free cash flow (FCF) to more than 50%, and plans to announce additional measures of more than 60 trillion won, including a special dividend, within the year. SK hynix shares stood at 1.5 million won as of the closing price that day, roughly half the 2.919 million won recorded on June 22.

3. Won Strengthens Despite Spike in U.S. Treasury Yields; "Could Reach Mid-1,300 Won Range"

- Key summary: In the Seoul foreign exchange market on the 19th, the won-dollar exchange rate closed at 1,397.7 won, down 14.1 won from the previous session, falling below 1,400 won for the first time in about 10 and a half months since October 2 last year. Even though the U.S. 30-year Treasury yield rose to 5.31% on the 18th local time, the market interpreted this as an expansion of the risk premium rather than a rise in yields. Increased dollar selling by semiconductor firms and offshore trading players also drove the rate lower. However, Cho Yong-gu, a senior researcher at Shinyoung Securities (001720.KS), suggested the won could form a short-term bottom around late August to September before rebounding to 1,400 won or the low-1,400 won range.

4. First-Half Operating Profit at KOSPI Firms Jumps 254%, Led by Samsung and SK hynix

- Key summary: Among 634 December-closing companies on the KOSPI market analyzed on a consolidated basis, first-half operating profit came to 388.1532 trillion won, up 254.15% from a year earlier. The combined operating profit of Samsung Electronics and SK hynix, at about 244.88 trillion won, accounted for more than 60% of the total, but even excluding the two companies, operating profit rose 75.61%. By sector, consolidated operating profit in electrical and electronics surged 674.92%, while six sectors including transport and warehousing and leisure and culture declined. In addition, operating profit in the securities industry jumped 163.37% to 9.2066 trillion won, the steepest growth among financial businesses.

5. Rate Hikes Have Only Just Begun, Yet Household Debt Tops 2,000 Trillion Won for the First Time

- Key summary: According to second-quarter 2026 household credit figures released by the Bank of Korea on the 19th, the balance at the end of the second quarter stood at 2,019.8 trillion won, up 25.9 trillion won from the previous quarter and topping 2,000 trillion won for the first time on record. Housing-related loans rose 12.2 trillion won to 1,190.8 trillion won, and other loans, including credit loans such as those used for leveraged investing, increased 12.8 trillion won to 700.5 trillion won. The Bank of Korea, after raising its base rate from 2.5% to 2.75% last month, has made further hikes official. As a result, the COFIX (Cost of Funds Index) rate for new loans reached 3.18% in July, its highest in one year and seven months, adding to the repayment burden.

6. Asset Managers Smile Amid ETF Boom; Mirae Asset and Samsung See Net Profit Double

- Key summary: With ETF (exchange-traded fund) net assets at one point surpassing 500 trillion won, the six largest asset managers all saw increases in first-half net profit. Mirae Asset Global Investments surged 177.4% to 906.3 billion won, ranking first among all managers, while Samsung Asset Management more than doubled from 51.6 billion won to 129.4 billion won. Samsung's results were led by its core management business, including 294.2 billion won in fee income, while Mirae Asset's were driven by overseas operations, including 769.1 billion won in equity-method gains. Set-up assets in domestic equity public funds stood at 112.9965 trillion won as of the 14th of this month, up 46.8811 trillion won since the start of the year, with index equity funds accounting for 94% of the increase.