Seoul Stocks: KOSPI and KOSDAQ Daily — 2026-10-17

Top developments

Foreigners Turn Net Buyers, Ending 9-Session Sell Streak

On October 16, the KOSPI rose 2.05% to 5,668.05, marking its first gain since October 6. This reversal was led by foreign investors, who recorded a net buy of 341.4 billion won, ending a nine-session streak of net selling. However, domestic individuals and institutions remained net sellers, dumping 485.9 billion won and 682.4 billion won respectively, indicating that the recovery was driven primarily by foreign bargain-hunting rather than broad domestic confidence.

KOSDAQ Surges 4.46% as Sidecar Triggers

The KOSDAQ index jumped 4.46% to 794.78, significantly outperforming the KOSPI. The surge was strong enough to trigger the buy-side sidecar mechanism, a volatility halting tool, as investors aggressively bought back into mid-cap tech and biotech stocks after the previous day’s crash. This sharp rebound suggests that the October 15 sell-off was viewed by many local traders as an overreaction, particularly in the high-beta KOSDAQ sector.

Samsung and SK Hynix Recover Amid Valuation Concerns

Samsung Electronics closed at 215,500 won, up 2.62%, while SK Hynix rose 0.79% to 1.272 million won on October 16. These gains came after a brutal October 15 session where both chipmakers sank over 10%, dragging the KOSPI down by 7.57% and triggering circuit breakers. Despite the recovery, KED Global reports that the KOSPI’s forward P/E ratio has hit a 26-year low, with investors still reluctant to buy aggressively due to doubts over the sustainability of AI-driven chip demand.

Retail Investors Buy the Dip in Chipmakers

While foreign investors sold approximately 21 trillion won worth of stocks in October, retail investors (individuals) stepped in to buy over 7 trillion won of Samsung Electronics and SK Hynix shares since the start of the month. This shift contrasts with September, when retail investors had sold over 18 trillion won of these two stocks. Foreigners, meanwhile, have focused their October selling on the chip "twin tops," accounting for 87% of their total net selling in the KOSPI this year.

Local view

Local financial media highlighted the divergence between foreign and domestic flows. The Financial News noted that while foreigners returned to buying, the volume was modest compared to the massive institutional selling, suggesting the market has not yet fully stabilized. Chosun Ilbo emphasized that the rebound was partly fueled by comments from Nvidia’s CEO regarding AI investment, which helped ease immediate fears about a peak in AI spending. Segye Ilbo focused on the retail investor behavior, framing the October dip as a "buying opportunity" for individuals who had previously exited the market, signaling a potential floor for chip stocks in the short term.

Context & numbers

• KOSPI Close (Oct 16): 5,668.05 (+2.05%, +113.83 points).
• KOSDAQ Close (Oct 16): 794.78 (+4.46%).
• Foreign Net Flow (Oct 16): +341.4 billion won (First net buy in 9 sessions).
• KOSPI Plunge (Oct 15): -7.57% (Closed at 5,554.22); Circuit breakers triggered.
• KOSDAQ Plunge (Oct 15): -7.65% (Closed at 760.82).
• USD/KRW Rate: 1,331.4 won (Oct 16, down 13.2 won from previous close).
• Samsung Electronics (Oct 16): 215,500 won (+2.62%).
• SK Hynix (Oct 16): 1,272,000 won (+0.79%).

On the radar

• Regulatory Warning on Leveraged Bets: The Financial Supervisory Service warned investors on October 16 about the risks of trading offshore derivatives linked to Samsung and SK Hynix, noting that some bets are leveraged up to 200 times.
• SK Hynix Nasdaq Listing Speculation: Following rumors and reports of SK Hynix’s potential $26.5 billion Nasdaq debut, domestic regulators are facing pressure to clarify listing rules for mid-cap tech firms seeking US listings.
• Value-Up Programme Disclosures: Investors are awaiting the next round of Value-Up disclosures, with the July 29, 2026 list of "low valuation" companies still serving as a watchlist for potential shareholder return improvements.