A market maker shall provide bid and ask quotes of designated stocks during the period from five minutes after the opening to the closing of the centralized market of the TWSE, in accordance with the following operating regulations:
- A quote shall include the bid price and ask price. In terms of period of validity, the quote may not be canceled if not immediately satisfied, or canceled if not all quotes are immediately satisfied.
- The bid-ask spread quoted may not exceed 3%, as calculated as below:
(Bid-ask spread) = [(Ask quote) – (Bid quote)] / (Ask quote).
- No bid and ask quote may be less than five trade units, or the total amount shall be TWD 200,000 or above.
- A current quote shall be valid for at least 50% of the period from five minutes after the opening to the closing of the centralized market. The following periods that apply to designated stock may be excluded:
- periods where matching is postponed in accordance with Article 58-3, paragraph 6 or 8 of the Operating Rules of the TWSE.
- periods where the price disclosed is the price of a buy or sell limit order.
- periods where the best bid or ask price disclosed is the market value.
- The number of days of a valid quote that conforms to the preceding four subparagraphs in a month shall be at least 80% of the number of days a quote is required in said month. The number of days a quote is required means the number of trading days of a designated stock in the current month, exclusive of the following periods:
- periods where the designated stock is listed as a disposition stock.
- periods where the periodic call auction trading method is employed for the designated stock.
- other times approved by the TWSE where quotes are optional.