Auctions & Closing Mechanics

Read these first

1. 01Why Markets Use Call Auctions

   At the open and close, exchanges stop trading continuously and instead collect orders for a few minutes, then clear them all at a single price. That single step fixes problems continuous trading can't.

2. 02How The Uncrossing Price Is Computed

   The exchange has a book full of buy and sell limit orders at different prices and needs one number. The algorithm picks the price that trades the most shares, then breaks any tie by minimizing leftover imbalance and finally by distance from a reference price.

3. 03The IPO Opening Auction

   A stock's first trade ever is not a continuous market finding its footing, it is a single call auction that has to set a fair opening price with no prior trading history to anchor it.

4. 04Trading The Index Rebalance Close

   When an index provider changes its constituents or weights, every fund that tracks that index must trade at the same moment, the closing auction, creating some of the largest, most predictable liquidity events in markets.

Then the rest

1. 05Auction Versus Continuous Trading Liquidity
2. 06European Periodic Auction Books
3. 07How Good Is Opening Auction Price Discovery?
4. 08How Imbalance Maps To The Auction Print
5. 09How The Auction Book Interacts With The Continuous Book
6. 10Imbalance-Only And Auction-Only Orders
7. 11Indicative Price Drift During The Call Phase
8. 12MOC Cut-Offs And Late Order Rules
9. 13Negotiated Crosses And Price Check Rules
10. 14Price Dislocation In The Closing Auction
11. 15Random End Times And Auction Extensions
12. 16Static And Dynamic Price Bands
13. 17Tie-Breaks: Minimum Surplus And Reference Price
14. 18Why The Closing Auction Keeps Growing
15. 19Gaming The Auction Imbalance