Midpoint Order Matching Method

A midpoint order is designed to execute at mid-price in the KRX regular trading session. It is matched with other midpoint orders, limit orders, or market orders through continuous auction. Execution follows the standard price-time priority: price priority applies first, followed by time priority. Midpoint orders are not valid during single price auctions or when either the bid or ask price is unavailable. Their validity resumes during continuous auctions once both bid and ask prices are available.


[Example 1] Matching with Midpoint order
Asks Price Bids Execution Result
③100 3,515 <1> ④ - ⑤ : 50 shares at 3,502 KRW
<2> ① - ⑤ : 100 shares at 3,510 KRW
      (mid-price after execution: 3,512 KRW)
3,512
①100 3,510 ⑤200
④50(midpoint order) 3,502(mid-price)
3,495 ②200
[Example 2] Suspension and Resumption of Midpoint order
Asks Price Bids Execution Result
⑤100 3,515 <1> ① - ④ : 100 shares at 3,510 KRW
<2> ③Midpoint order suspended(No valid ask quote)
<3> After ⑤Limit order, ③Midpoint order reactivated(mid- price 3,512 KRW)
①100 3,510 ④500
3,502(mid-price) ③50(midpoint order)
3,495 ②200
3,400