If a limit order with a price better than the arithmetical mean remains on the order book, that price becomes the opening price.

If a limit order with a price better than the arithmetical mean remains on the order book, that price becomes the opening price.

• A. The price of that limit order that is better than the mean
• B. The arithmetical mean of the last two orders
• C. The last-executed price
• D. The reference price

Answer: (A)

Opening price is determined by what’s resting on the order book during the opening phase. The system calculates a mean as a reference price, but if there is a limit order on the book at a price that is more favorable than that mean and it stays unfilled, the opening price is set at that resting limit order’s price. This ensures the opening reflects the best available price shown by participants at the moment price discovery occurs, rather than an average that might not represent actual resting interest. The other options don’t fit because the mean of the last two orders isn’t about the resting book at opening, the last-executed price would only apply after a trade has taken place, and the reference price is a separate benchmark used for other rules, not the opening price.

Opening price is determined by what’s resting on the order book during the opening phase. The system calculates a mean as a reference price, but if there is a limit order on the book at a price that is more favorable than that mean and it stays unfilled, the opening price is set at that resting limit order’s price. This ensures the opening reflects the best available price shown by participants at the moment price discovery occurs, rather than an average that might not represent actual resting interest.

The other options don’t fit because the mean of the last two orders isn’t about the resting book at opening, the last-executed price would only apply after a trade has taken place, and the reference price is a separate benchmark used for other rules, not the opening price.