Periodic call auction
Auction principles
  • Periodic call auction is a transaction method where all bids and offers submitted during a certain period of time are queued in the limit order book and matched at a single price in accordance with the principle of price and time priority. Every periodic call auction is closed at the random time that KRX decides within 30 seconds from the closing point in order to prevent any unfair trade.
Pricing and Matching
  • The single price is determined at a level at which all bids with prices higher than the price and all offers with prices lower than the price are filled.
  • After the price determined priority shall be set by price order and time order, it is matched by the priority. But if it is the upper limit price or lower limit price, the priority order shall be set by consignment or quantity order. And the prior quantity shall be allocated first. Ex. 100, 500, 1000, 2000 shares.
Application
  • Determining opening price for common stock (opening single price)
  • Closing price of normal stock( closing single price )
  • Setting the initial price for newly listed or re-listed stock (single price trading on listing day)
  • Resuming after Circuit Breakers
  • Resuming after trading halt
  • In case of trading issues designated as administrative issue or issues to be delisted
Continuous Auction by multiple price
Trading principle
Order matched if there is any possible counter order applying price priority and time priority.
Pricing
Matching the highest buying order with the lowest selling order and set the price as earlier order base according to price priority and time priority.
Application
All transaction from opening after before-hours single price transaction to closing before after-hours single price transaction.
Off-hours periodic call auction by single price
  • The offers and bids are submitted at 10-minute intervals from the starting point of off-hour single price auction and the transaction is executed (single price auction with 10-minute intervals and total 12 trade execution)
  • Price change limit is ±10% of the closing price in one day and the offers and bids are matched according to price and time priority.