What it is
The Korean market caps how far a stock can move in one day. The highest allowed price is the upper limit (limit up) and the lowest is the lower limit (limit down). Since June 2015 the band is ±30% of the base price, usually the previous close.
How it is set
The base price plus or minus 30% is adjusted to a valid tick, so the actual limit can be slightly less than exactly 30%.
What to keep in mind
When buy orders pile up unfilled at the upper limit, Korean investors call it "limit-up with remaining bids". Different bands apply in special cases such as the first day of a new listing or delisting liquidation trading.
This explanation is general information, not investment advice. Rules reflect September 2026 and may change; check official exchange and broker notices.