KOSPI plunges intraday, 73% win-rate account predicts it will be difficult to reach a new high before 2028

According to PolyBeats monitoring, on the prediction market Polymarket, the probability of "the Korea Composite Stock Price Index (KOSPI) hitting an all-time high before 2028" has fallen from 70% a month ago to the current 28.5%. The market rules require that before 23:59 KST on December 31, 2027, the KOSPI must exceed 9,385.59 points intraday or at the close during regular trading hours on the Korea Exchange.

KiernanMeister bought $1.76k of "No" on "the Korea Composite Stock Price Index (KOSPI) hitting an all-time high before 2028," at a buy probability of 34.73%. This trader has made a total of 11 trades in the Korean sector, with a 73% win rate, PnL +$2.8k, and this bet is 8.17 times the median bet size.

As of publication, the KOSPI is around 5,925.49 points intraday, and still needs to rise 58.4% to reach its previous high of 9,385.59 points. On October 6, The Diplomat cited South Korea's September data saying semiconductor exports exceeded $60b for the first time, up 83.5% year-over-year; Samsung Electronics and SK Hynix together account for about 66% of KOSPI market capitalization, and if AI and memory demand continue to drive upward revisions to the two companies' earnings, the index has the flexibility for a rapid recovery.

On October 13, Yuanta Securities set its base-case range for the KOSPI in 2027 at 6,000–10,000 points, derived from listed companies' net profit of 1,160 trillion won and a target P/E ratio of 7.3 times; in the optimistic scenario, it sees a high of 12,000 points.

But Yuanta's base path itself also illustrates timing risk: it expects the index to still broadly trade in the 6,000–8,000 point range in the first half of 2027, rise to 7,500–9,000 points only in the third quarter, and challenge 8,500–10,000 points only in the fourth quarter.