• Font Size:
  • S
  • M
  • L

Relevant Laws

Title:Operating Rules of the Taiwan Stock Exchange Corporation (2021.01.29)
Article 58-3     The competitive auction for trading orders shall be divided into call auction and continuous trading. The first matching in the current session shall be done by call auction, and subsequent matching shall be done by continuous trading until a period of time before market closing, during which all the trading quotes shall be accumulated and matched by call auction.
    Trade prices of call auction shall be determined based on the following principles:
  1. Satisfying the maximum trade volume such that buy orders with prices higher than the determined price and sell orders with prices lower than the determined price shall be all satisfied.
  2. Where there are buy and sell orders with prices equal to the determined price, at least one side shall be all satisfied.
  3. Where two or more prices conform to the principles set forth in the preceding two subparagraphs, the price closest to the most recent traded price in the current session shall be used. If there is not yet any traded price in the current session, the price closest to the auction reference price at market opening of the current session.
    Trade prices of continuous trading shall be determined by each buy order or sell order that is entered based on the following principles:
  1. When the price of a buy order entered is higher than or equal to the minimum price of a sell order previously entered, orders shall be satisfied from the lowest to the highest price of sell order, in that order, until orders are all satisfied or until the price of the buy order currently entered is lower than the price of the unsatisfied sell order.
  2. When the price of a sell order entered is lower than or equal to the maximum price of a buy order previously entered, orders shall be satisfied from the highest to the lowest price of buy order, in that order, until orders are all satisfied or until the price of the sell order currently entered is higher than the price of the unsatisfied buy order.
    The aforesaid auction reference price at market opening of the current trading session shall be determined by the following principles:
  1. Use the closing price for the preceding day.
  2. Where there is no closing price for the preceding day, the auction reference price shall be determined by the following principles:
    1. If, on the preceding day, the highest buy order price at the close of market was higher than the auction reference price at the opening of market, use the highest buy order price.
    2. If, on the preceding day, the lowest sell order price at the close of market was lower than the auction reference price at the opening of market, use the lowest sell order price.
    3. When neither of the above circumstances applies, use the auction reference price at the opening of market of the preceding business day.
  3. In the case of an initial listing, price adjustment due to ex-rights or ex-dividend trading, or resumption of suspended trading, use the price arrived at by processing, pursuant to Article 62 herein, the reference price as set in accordance with Article 59, 59-1, 67, 67-1, or 67-2, or other rules.
    The opening price of a security is the price of the first matched trade for the current session. Trading orders entered prior to market opening that are unexecuted shall continue to be matched in the order as originally randomly assigned by the computer. The closing price shall be the price of trades matched upon accumulation of all trading orders over a period of time prior to market closing. Where unexecuted, the closing price shall be the last traded price during the current session.
    Except securities that are newly listed common stocks during the period when no price fluctuation limit is imposed, or securities for which extended matching intervals have been implemented under the bylaws or rules of the TWSE, or securities for which the opening auction reference price is lower than a certain price, during the period from the first matched trade of a security during the current session until the period of time prior to market closing, if any execution price as test-calculated prior to each matching fluctuates beyond 3.5% of the reference price:
  1. If a trading order entered is a limit order and is valid for the current day, except that an order whose execution price as test-calculated is within the price range and shall be satisfied immediately, the TWSE shall at the same time postpone the matching of the security for two minutes, and continue to accept entries, cancellations, and changes of trading orders for that security. Matching will then proceed by call auction at the conclusion of the postponement period.
  2. If a trading order entered is a limit order which will be canceled if not immediately satisfied in one trade, is a market order and is valid for the current day which will be canceled if not immediately satisfied in one trade, except that an order whose execution price as test-calculated is within the price range and shall be satisfied immediately, the remaining unsatisfied volume of the trading order entered is canceled.
  3. If a trading order entered is a limit order which will be canceled if not all order is immediately satisfied, or is a market order which will be canceled if not all order is immediately satisfied, the trading order entered is all canceled.
    The reference price in the preceding subparagraph shall be determined by the following principles:
  1. Within five minutes after the first matching for the current session, the reference price is the price of the first matched trade. In the absence of a trade price in the first matching, the opening auction price shall be the reference price.
  2. After the first five minutes of the first matching for the current session, prior to each matching, a weighted average price is calculated based on the price and volume of all trades for the five-minute period immediately before the entry time of the order. In the absence of a trade price in the five minutes, the most recent trade price shall be used. In the absence of a most recent trade price, however, the opening auction price shall be the reference price.
  3. After the first matching for the current session, in the event of a postponement of matching of a security in the first subparagraph, within the five minutes after the conclusion of the postponement period, the trade price of the call auction during the session is the reference price. In the absence of a trade price during the session, however, the reference price shall be calculated in accordance with the preceding subparagraph.
    If, during the 1 minute prior to market opening or market close for a security, any given computed execution price fluctuates beyond 3.5 percent from the previous computed execution price (if there is no previous computed execution price available 30 minutes before market opening, the fluctuation shall be based on the auction reference price at market opening; if there is no previous calculated execution price available a period of time before market closing, the fluctuation shall be based on the most recent trade price; if there is no most recent trade price available, the fluctuation shall be based on the auction reference price at market opening), the first matched trade for the current session, or the matching at market close, for that security is postponed. For a security for which the first matched trade for the current session is postponed, matching and execution for the security will proceed sequentially after 2 minutes of postponement. For a security for which the matching at market close is postponed, entries, cancellations, and changes of trading orders for that security will continue to be accepted from 1:31 p.m. to 1:33 p.m., and matching and execution will then proceed sequentially at 1:33 p.m. However, this restriction shall not apply to securities for which extended matching intervals have been implemented under the bylaws or rules of the TWSE, securities for which the opening auction reference price is lower than NT$1, call (put) warrants, or company warrants.