# How is a stock's closing price determined if there are multiple possible prices during the closing auction?

It is my understanding that during the closing auction, the selected closing price is the price at which the most number of shares would trade. But what happens if there is more than one such price? Suppose person X places a limit on close (LOC) order to buy 100 shares at \$11, person Y places a LOC order to sell 100 shares at \$9, and X and Y are the only participants in the closing auction. All prices \$9 <= p <= \$11 are valid closing prices. How would the closing price be chosen in this case?

(If the answer depends on jurisdiction, I would like an answer for the NYSE, Nasdaq, Hong Kong Exchange and/or the London Stock Exchange.)

• If it wasn't the closing auction, lets say it was an hour before the market closed, what would the price of the shred be? Sep 2, 2022 at 10:16
• @mhoran_psprep During continuous trading, if X placed his order first, I think the price would be \$11. If Y placed his order first, I think the price would be \$9. Is price-time priority used during the closing auction too?
– Flux
Sep 2, 2022 at 10:31