Daily Pulse: September 23, 2026
KOSPI +0.90% | KOSDAQ +1.21% | Foreign cash net sold KRW 541B (~$396M): Samsung Electronics absorbed KRW 1.29T (~$944M) in foreign buying while SK Hynix drew KRW 1.18T (~$864M) in foreign selling
The Number That Matters
Foreign net selling of KRW 541B (~$396M) conceals a structure that is almost impossible to read as directional. Foreign investors bought KRW 1.29T (~$944M) of Samsung Electronics and sold KRW 1.18T (~$864M) of SK Hynix in the same session. The net is noise. The composition is the story. The KOSPI opened at 7,153, touched a session high of 7,153, and closed at 7,080, a 1.0% give-back from the open that the headline percentage does not show.
Where the Money Went
Foreign buyers concentrated in Samsung Electronics at KRW 1.29T (~$944M), Samsung Electronics preferred shares at KRW 140B (~$102M) and SK Square at KRW 38B (~$28M). Against that, SK Hynix absorbed KRW 1.18T (~$864M) in foreign selling and Doosan Enerbility drew KRW 129B (~$95M). Institutions bought KRW 334B (~$245M) net; financial investment contributed KRW 317B (~$232M) of that total, alongside pension funds at KRW 68B (~$50M), while investment trusts sold KRW 69B (~$51M). Program trading sold KRW 715B (~$524M) net on the day, with non-arbitrage accounting for KRW 788B (~$578M) of that sell against KRW 73B (~$54M) in arbitrage buying. Retail sold KRW 1.43T (~$1.0B), with Samsung Electronics at KRW 2.17T (~$1.6B) the single largest exit. Foreign and institutional conviction overlapped in Samsung Electronics, SK Square and SK Innovation simultaneously, with retail delivering the volume to both.
Why the Market Moved
1. SOX rose 2.06% overnight, providing a semiconductor tailwind; foreign buying concentrated in Samsung Electronics rather than SK Hynix.
2. Institutions bought KRW 334B (~$245M) net, absorbing retail selling of KRW 1.43T (~$1.0B), with pension funds contributing KRW 68B (~$50M).
3. Foreign futures bought 1,356 contracts while cash sold, cash and futures moving in opposite directions for the session.
The Uncomfortable Question
Foreign investors bought KRW 1.29T (~$944M) of Samsung Electronics and sold KRW 1.18T (~$864M) of SK Hynix on the same day that SOX rose 2.06%. The Samsung Electronics gross buy is the largest foreign inflow in a single name in recent sessions, yet total foreign cash remained a net sell of KRW 541B (~$396M). Whether the Samsung Electronics concentration represents the start of a sustained position rebuild or whether the SK Hynix exit will absorb any gains from that rebuild cannot be determined from one more session of near-zero net foreign cash.
Key Disclosures Today
KT&G filed a treasury share acquisition decision on DART; no KRW amount was disclosed in the filing summary.
KoreaAlpha Take
Sell-side desks will call the Samsung Electronics foreign gross buy of KRW 1.29T (~$944M) the confirmation they needed. It is not. The watchpoint established in the prior session was foreign net cash in SK Hynix turning positive. Today it came in at negative KRW 1.18T (~$864M), the largest single foreign sell on the day. Samsung Electronics and SK Hynix absorbed nearly identical gross flows in opposite directions, producing a foreign headline net that tells almost nothing about whether capital is returning to Korean equities structurally or rotating within the semiconductor complex. The unresolved question is whether the Samsung Electronics gross buy consolidates into a two-session pattern or whether SK Hynix selling resumes at comparable scale and cancels it again. The trade is simple: watch whether foreign net cash in SK Hynix turns positive in the next session.
Data sources: Korea Exchange, DART, 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 1.63 trillion (~$1.2B) net bought on this session, sits with other corporations and other foreign investors, categories this report does not collect.
