Key facts
- A buy-side sidecar is triggered when the KOSPI 200 Futures Index rises 5 percent or more for at least one minute.
- SK hynix Inc. reported record-high revenue and operating profit for the third quarter.
- SK hynix Inc. announced a shareholder return program worth more than 100 trillion won (US$75.3 billion) for 2026.
South Korea's bourse operator, the Korea Exchange (KRX), activated a buy-side sidecar for the benchmark Korea Composite Stock Price Index (KOSPI) on Wednesday, October 28, 2026, as the index experienced a sharp rise. Program trading for KOSPI-listed shares was suspended for five minutes at 9:53 a.m. The KOSPI opened 2.23 percent higher and subsequently added 255.92 points, or 4.54 percent, to reach 5,894.26 as of 9:55 a.m. This rally was fueled by strong artificial intelligence (AI)-driven semiconductor earnings, particularly from SK hynix Inc., which reported record-high revenue and operating profit for the third quarter and announced a significant shareholder return program. A buy-side sidecar is typically triggered when the KOSPI 200 Futures Index rises 5 percent or more for at least one minute.