Non-Opening is triggered when which condition occurs?

Non-Opening is triggered when which condition occurs?

• A. When there are no quotes on the opposite side
• B. When the book contains only limit orders
• C. When the market ignores the auction
• D. When in CLOB and QDM there are market orders still left in the order book in the auction

Answer: (D)

Non-Opening happens because the auction can’t produce a clear price due to aggression in the book. In a CLOB and QDM, the opening auction tries to discover a price that clears the maximum possible volume by matching orders across sides. If there are market orders still in the auction book, they are ready to trade immediately against whatever is available, which prevents a single, fair cross price from forming. Since no clearing price can be established, the session is labeled Non-Opening and trading continues in the regular market until conditions allow another auction or normal trading to resume. The other scenarios don’t by themselves trigger Non-Opening: having no quotes on the opposite side, the market ignoring the auction, or the book containing only limit orders can still allow or be resolved in the auction under different rules, but it’s the presence of remaining market orders that stops the price discovery process.

Non-Opening happens because the auction can’t produce a clear price due to aggression in the book. In a CLOB and QDM, the opening auction tries to discover a price that clears the maximum possible volume by matching orders across sides. If there are market orders still in the auction book, they are ready to trade immediately against whatever is available, which prevents a single, fair cross price from forming. Since no clearing price can be established, the session is labeled Non-Opening and trading continues in the regular market until conditions allow another auction or normal trading to resume.

The other scenarios don’t by themselves trigger Non-Opening: having no quotes on the opposite side, the market ignoring the auction, or the book containing only limit orders can still allow or be resolved in the auction under different rules, but it’s the presence of remaining market orders that stops the price discovery process.