This week's market action has been characterized by extreme swings, with the South Korean Kospi index surging 14%, marking its largest one-day jump, according to LSEG data. This rebound, mirrored by significant gains in SK Hynix and Samsung Electronics, followed a powerful rally in U.S. technology stocks, fueled by strong earnings from Microsoft, Amazon, and Meta, which reinforced robust AI infrastructure spending expectations. Foreign investors were identified as the primary drivers of this rally, amplified by short-covering and rebalancing by leveraged ETFs. This volatile environment led one analyst to describe the Korean stock market as having "bipolar disorder," swinging from panic to euphoria almost overnight, indicating a violent reversal of a crowded sell-off.
In contrast, AI-driven market sell-offs severely impacted quantitative investment strategies. The Hong Kong-based Jupiter Tactical Trading Fund, managing approximately $186 million earlier this year, saw its value tumble by over 40% in July, despite having gained around 60% in the first five months of the year. Similarly, Situational Awareness, a hedge fund founded by former OpenAI researcher Leopold Aschenbrenner, suffered heavy losses and was forced to significantly reduce its public equity exposure. These funds, particularly vulnerable due to their reliance on momentum strategies and leverage (Jupiter used 2-4x leverage), were hit hard as sentiment reversed in crowded AI trades across the globe.
However, a significant intervention by Ken Griffin's Citadel helped stabilize the AI sector. Citadel acquired over $10 billion worth of public holdings from Situational Awareness, which was facing margin calls. This move, despite Griffin's previous skepticism about AI technology, sent AI stocks soaring, with the iShares Semiconductor ETF (SOXX) jumping 8.5%, retracing previous losses. The bailout was interpreted by investors as a potential bottom in the AI sell-off, sparking a relief rally on Wall Street and causing many of Situational Awareness's top holdings, including IREN, Sandisk, and CoreWeave, to rise by over 20%. This event removed a major seller from the market, boosting investor confidence.
