Daily Pulse: September 10, 2026
KOSPI -0.25% | KOSDAQ +0.79% | Foreign cash and futures both net sold: KRW 3.75 trillion (~$2.8B) cash, 7,086 contracts
The Number That Matters
Foreign cash sold KRW 3.75 trillion (~$2.8B) and futures sold 7,086 contracts on the same session. The three-session run of foreign cash and futures buying in the same direction ended on Wednesday, when cash sold and futures bought. Today both legs sold together. SK Hynix and Samsung Electronics absorbed 88% of total foreign selling, at KRW 1.77 trillion (~$1.3B) and KRW 1.55 trillion (~$1.2B) respectively.
Where the Money Went
Foreign net selling of KRW 3.75 trillion (~$2.8B) concentrated in SK Hynix at KRW 1.77 trillion (~$1.3B) and Samsung Electronics at KRW 1.55 trillion (~$1.2B), together representing 88% of the total and 11.8% of KOSPI turnover. Foreign buying names, Samsung Electronics preferred shares at KRW 143B (~$107M), SK Square at KRW 126B (~$94M) and Hyundai Mobis at KRW 70B (~$52M), summed to KRW 339B (~$253M), under a tenth of the KRW 3.57 trillion (~$2.7B) sold across the three largest foreign sell names. Institutions bought KRW 1.97 trillion (~$1.5B) net, with securities firms at KRW 1.30 trillion (~$967M) the largest component; that figure includes program trading and trust-based buybacks not separated in this data. Pension funds sold KRW 136B (~$102M). Retail bought KRW 110B (~$82M) net, a near-neutral position.
Why the Market Moved
1. Foreign cash and futures both sold in size, with semiconductor concentration at 88% of the foreign total; institutions absorbed the outflow and kept the KOSPI at a -0.25% close.
2. Today was a quadruple witching session in Korea, with derivatives expiry typically amplifying intraday swings; the KOSPI traded as low as 6,898.45 before closing at 7,033.92, a recovery of 135 points from the session low.
3. The US 10-year yield sat at 4.83% (+0.03%p), maintaining pressure on growth and semiconductor valuations.
The Uncomfortable Question
Institutions bought KRW 1.97 trillion (~$1.5B) and kept the index near flat. The question is whether that absorption reflects genuine conviction or securities-firm program flows and trust-based buybacks that cannot be separated in this data. Pension funds sold KRW 136B (~$102M) net. Foreign cash selling extended to a second session. If institutions step back tomorrow, there is no structural bid visible in today's data.
Key Disclosures Today
No material DART filing warrants separate treatment today.
KoreaAlpha Take
The sell-side will note that institutions held the index together on a quadruple witching day and call that constructive. The data says something harder: foreign cash and futures sold in the same direction, semiconductor selling was 88% concentrated in two names, and the institutional cushion rests on a component that bundles program trading with discretionary buying in a way this report cannot untangle. Pension funds sold again today. Whether foreign cash net selling extends into a third session is the question the data cannot settle. The trade is simple: watch whether foreign net cash trade remains negative tomorrow.
Data sources: Korea Exchange, DART, Naver Finance, Bloomberg
Research only. Not investment advice. KoreaAlpha does not provide personalised recommendations.
Flow figures are KRX investor-type trading value across all listed boards (KOSPI, KOSDAQ, KONEX), common stock only, excluding ETF, ETN and ELW; institutions = the KRX institutional total investor type. Foreign, institutional and retail do not sum to zero: the balance, KRW 1.66 trillion (~$1.2B) net bought on this session, sits with other corporations and other foreign investors, categories this report does not collect.
