BME launches SpainAtMid, a dark order book with zero latency dark to lit sweep order functionality

• This new functionality will allow trading participants to seek contra liquidity in larger size, whilst minimising the price impact of resting orders or seeking price improvement on aggressive orders.

Starting in December, BME will incorporate a new functionality to its Smart platform called SpainAtMid, a non-displayed pool which will allow the trading of equities at the BBO mid-point of BME's central limit order book (CLOB). This functionality will be available during the continuous trading phase and support the execution of resting, immediate and sweep orders.

A separate MIC Code has been registered for SpainAtMid and it has been designed to operate on the same atomic matching cycle as the BME CLOB. This ensures that there is no latency cost in seeking price-improvement at the mid-point when sweeping through SpainAtMid to aggress a displayed price on the CLOB. Also it ensures that trades are always executed at the current PBBO mid-point price (i.e. never at a stale price).

Trading participants will be able to specify how their market and limit orders interact with SpainAtMid in two ways:

• Direct: Orders can be flagged to be routed to SpainAtMid only, where they will remain until execution at the prevailing mid-point or until they are cancelled.
• Sweep: Orders can be flagged to be routed firstly to SpainAtMid, (for execution at the prevailing mid-point) and then any remaining unexecuted portion will be routed to the Central Limit Order Book where it will remain until it is either fully executed or cancelled.

According to the current estimated release schedule, this new functionality will be implemented in the test environment on September 30, 2024 and will go live into production on December 9, 2024.