Base Price

Base price is the price used as the basis for determining the price limitations of stocks, ETFs, and beneficiary certificates for the day. In the KRX market, the previous day's closing price is generally the base price. As such, price fluctuation limits for the day is 30% higher and lower than the previous day's closing price.

Closing prices mean the prices lastly traded at the regular session. If there was not a trade during the previous day, the base price of the previous day is deemed as the closing price.

However, in cases where there is a corporate action such as capital increase by new shares (excluding the 3rd party allocation method and the public offering method), bonus stock, stock dividend, stock split, reverse stock split, etc., it is needed to reflect to the base price the changed value of securities issue before and after the corporate action. Therefore, it this case, the KRX adjusts the base price to an appropriate theoretical price calculated through a certain formula.

Example: Stock Split

For a stock of which previous closing price is KRW 10,000 and having a stock split of 1:10, the next day's base price will be adjusted to KRW 1,000. If the total shares issued are 1,000 shares before the split, the total shares will be 10,000 after the split and therefore, the adjustment in that base price makes the market capitalization the same.

Market capitalization before the split: KRW 10,000 x 1,000 Shares = KRW 10,000,000
Market capitalization after the split: KRW 1,000 x 10,000 Shares = KRW 10,000,000
Base Prices of Opening Prices Method

In case where the previous day's closing price is not available or it is difficult to calculate the appropriate theoretical price in such cases as new listing, capital reduction, relisting and listing change after corporate spin off, new listing of preferred shares, etc., 'Opening Price Method' is applied where the opening price determined in the market through a single price call auction is adopted as the base price for the day. In this case, the first price executed by the bid and ask orders received within a certain range of prices during the call auction period from 08:00 to 09:00 is adopted as the base price. After determining the base price at 09:00, trade matching is conducted like any other issues within the daily price limits based on that base price.

Appraisal Price and Price Range of Orders for the Opening Price Method

For those issues applying opening price method, the price range of orders placed to determine the first price (base price) is set wider than usual so that the equilibrium price is easy to find. Also, to prevent price distortion from too wide price range, the KRX sets an appropriate appraisal price and the range of quotation prices.


The appraisal price is the price to which the price range is set so that the quotations participate in the first price call auction within the range. For instance, in the case of a newly listing issue to which a price range of 90% ~ 200% of the appraisal price is applied, KRW 10,000 of appraisal price means the quotation prices submitted to determine the first price are limited within the range of KRW 9,000 ~ KRW 20,000.

Criteria for Determining the Appraisal Prices and Order Prices Range
Criteria for Determining the Appraisal Prices and Order Prices Range
Issues Appraisal Price Quotation Price Range Issues
New listing of common Stocks General stocks Public offering price 90%~200%
Holding company (holding a listed company as a wholly-owned subsidiary) (Sum of market capitalization by share class of wholly-owned subsidiary on the last trading day + total net asset value by share class of the wholly-owned unlisted subsidiaries) / total number of shares of all the share classes 90%~200%
(50%~200% in case where the book value of the listed company is less than 25% of the total assets of the holding company)
Other Stocks Net asset value per share 50%~200%
Relisting and listing change Relisting of new companies incorporated by spin-off and merger after spin-off and listing change of existing companies In case where the net asset values of issues applying for the listing change and relisting are positive (+):
  • Spin-off: (last trading day's market capitalization of each share class before spin-off x net asset split ratio) / number of shares by class after spin-off
  • Merger after spin-off:
  • {∑(market capitalization of each share class before spin-off and merger on the last trading day x net asset split ratio)} / number of shares by class after the merger after spin-off
50%~200%
However, in case where a large sum of shares are issued
via capital increase by the allocation to a third party, merger, transfer of business assets, etc., KRW 1~200%
In case where the net asset values of the listing change and relisting issues are not positive:
Relisting issue: no appraisal price KRW 1~last trading day's closing price
Listing change issue:
  • In case where the net asset value is positive (+): net asset value per share
  • In case where the net asset value is not positive: no appraisal price
50%~200%
KRW 1~(market capitalization before spin-off / number of shares of the new company)
Merger between listed companies establishing a new company Total market capitalization of all the share classes as of the last trading day before the merger / total number of shares of all the share classes after the merger 50%~200%
Listing change after capital decrease
  • Stock buyback from minority shareholders: {(Previous day's closing price x number of shares before the capital decrease)-(stock price paid to minority shareholders x number of shares for buyback)} / number of shares after the capital decrease
  • Capital decrease without consideration: Previous day's closing price × consolidation ratio or retirement ratio for minority shareholders
50%~150%
However, in case where a large sum of shares are issued at a low price
via capital increase by the allocation to a third party, merger, transfer of business assets, etc., KRW 1~150%
Preferred stocks New listing, Relisting and listing change Public offering price- However, if there has not been a public offering for the issue, the simple arithmetic average of the appraisal prices of the public offering prices of other preferred stocks with public offering. If there is not a preferred stock issue that had a public offering, the appraisal price of common stocks. 50%~200%
Initial listing of preferred stocks Public offering price
- If there has not been a public offering for the issue, the base price of the common stocks
50%~200%
Initial listing of preferred stocks of different class Public offering price
- If there has not been a public offering for the issue, the simple arithmetic average of the base prices of the already listed preferred stocks.
50%~200%
For details, please refer to Annex 1 of the Enforcement Rules of the KOSPI Market Business Regulation