In an unprecedented "bull market" with KOSPI and KOSDAQ surging day after day, the number of short-term overheated stocks has also increased significantly.
According to the Korea Exchange (KRX) on Feb. 1, a total of 41 stocks in the domestic market were designated as short-term overheated stocks last month (Jan. 2–30).
This is 10 more (32.3%) than in January a year earlier, when there were 31.
A stock is subject to designation as a short-term overheated stock when ▲ the closing price for the day rises 30% or more compared with the average closing price of the previous 40 trading days ▲ the average turnover over the most recent two trading days increases 500% compared with the previous 40 trading days ▲ the average intraday volatility over the most recent two trading days increases 50% compared with the previous 40 trading days. If the overheating pattern persists after a designation notice, the stock is designated definitively.
Once definitively designated as a short-term overheated stock, it is traded only through single-price auctions at 30-minute intervals for three trading days. The sharp increase in such designations comes as the domestic market has continued a daily rally after surpassing "5,000 KOSPI" and "1,000 KOSDAQ."
From Dec. 30, 2025, the last trading day of last year, through the 30th of last month, KOSPI rose 24.0%. Over the same period, KOSDAQ gained 24.2%.
By market, 20 stocks on the main board and 21 stocks on KOSDAQ are currently designated as short-term overheated stocks. In January last year, 21 stocks on the main board and 10 on KOSDAQ were designated.
Typically, most short-term overheated stocks came from KOSPI, but due to the recent surge in KOSDAQ, the designation ratio between KOSPI and KOSDAQ stocks was nearly even last month.
Large-cap leaders Samsung Electronics and SK hynix are at the forefront as stocks hitting record highs pour in. In the domestic market, a total of 192 stocks hit at least one 52-week intraday high last month.
SK hynix closed at 909,000 won on the 30th of last month, breaking above the 900,000-won level for the first time ever.
Brokerages noted that a change in the market's character could emerge in February. Kim Yong-gu, a researcher at Yuanta Securities Korea, said, "With successive overheating in prices, sentiment and flows, the market's character could shift to becoming sensitive to negatives that have not been cyclically priced in and less responsive to positives that have been priced in early," adding, "The Lunar New Year holiday gap could also spur a breather in the market."
Kim projected, "KOSPI in February will move at a neutral level within the 4,800–5,200 range," adding, "There could be a reconciliation between prices and valuation."