Two separate regime events produced one day of record gains. The KOSPI closed Friday at 6,595.45, up 1,001.89 points or 17.91% — the largest single-day gain in the index's history, surpassing October 2008's 11.95% record [1]. Amazon surged 15%, its biggest single-day move in a decade [2]. Both happened on the first full trading day after the Fed's fractured hold.
The KOSPI is a rule-change story. Amazon is an earnings story. The day is a post-hold market-answer story. All distinct, all on the same calendar page.
The KOSPI: A Rule-Change Rally
SK Hynix closed at 1,718,000 won, up 29.95% — its daily upper price limit, the first time it hit the limit in about 17 years since January 2009 [1]. Samsung Electronics closed at 262,500 won, up 26.81% [1]. Samsung Electro-Mechanics and SK Square also rose to their daily limits [1].
The trigger was Korea's leveraged-ETF rule change, which took effect Friday and restricted the kind of single-stock leveraged bets that had amplified the KOSPI's July decline. The rule change forced an unwind of short positions, producing a mechanical squeeze rather than a fundamental re-rating [1].
Foreign investors net-bought over 7 trillion won in KOSPI shares — more than double the previous single-day record of 3.14 trillion won [1]. Retail investors net-sold approximately 7 trillion won, taking profits on the rally they had been forced out of by the rule change.
The KOSPI had fallen three consecutive days before Friday's surge, losing more than 17% in that stretch. July's total decline reached approximately 22.4%, the second-largest monthly drop in the index's history after October 1997's 27.2% [1]. Friday's rally recovered a significant portion of that loss in a single session.
Amazon: The Earnings Receipt
Amazon's 15% surge came after the company reported quarterly results that included 37% growth in AWS and a $220 billion annualized capital expenditure run rate [2]. The results confirmed robust AI infrastructure demand through 2027 and beyond, according to analysts.
The stock's move was the biggest single-day gain in a decade. It came on the first full trading day after the Fed held rates steady at 3.50%-3.75% — a hold the paper carried Wednesday as the "fractured hold," with hawks citing PCE at 5.1% and doves citing GDP halving to 1.5% [3].
Amazon's negative free cash flow print from the prior quarter — the second negative-FCF hyperscaler after Alphabet — was the July 30 frame. Friday's surge suggests the market is pricing the AI capex cycle ahead of the cash-flow consequence.
The Post-Hold Market Answer
The KOSPI and Amazon surges happened on the same day as the first full trading session after the Fed's hold. Brent crude sat near $89.5 with IRGC tanker stops at Hormuz [2]. The oil premium and the equity rally coexist — the market is pricing AI demand and war risk as separate layers, not a single narrative.
The paper's July 30 GDP article carried the one-print-two-receipts frame on the Fed's fractured hold. Friday's market action is the market's answer: two regime events, two record gains, one calendar page.
What the Paper Knows and Does Not Know
The paper knows: the KOSPI closed at 6,595.45, up 17.91% (record); SK Hynix hit its daily limit; Samsung rose 26.81%; Amazon surged 15%; foreign investors net-bought 7 trillion won; the rally followed the Fed's hold and Korea's ETF rule change.
The paper does not know: whether the KOSPI's rule change is a one-day squeeze or a structural re-rating; Amazon's FCF trajectory post-Anthropic gain; and the conflicting Brent crude snapshots ($86.83 vs. $92.27 from different sources on the same day).
The market's answer to the fractured hold came in two currencies — won and dollars — and from two different regime events. The paper carries both as distinct records.
-- HENDRIK VAN DER BERG, Brussels