- TOP – A TOP order has a price that betters the market at the time the order is received and is therefore designated as having priority. Only a single buy order and a single sell order can have TOP priority at any given time. Orders having TOP priority match first regardless of size. For details of TOP Min, TOP Max, and TOP Percentage please see: CME Globex Matching Algorithm Steps - TOP.
- LMM – CME Designated Lead Market Makers are each allocated a configurable percentage of an aggressor order quantity before the remaining quantity passes to the next step.
- Split – Based on product parameters, quantity is split between a FIFO step and a Pro Rata step. Product parameters can be zero for either FIFO or Pro Rata. The total percentage of quantity split between FIFO and Pro Rata will always equal 100%.
- FIFO – Quantity is distributed to resting orders on a first in, first out basis (earlier timestamped orders receive fills before later timestamped orders).
- Pro Rata – Quantity to be matched is multiplied by each resting order's pro-rated percentage to calculate allocated trade quantity. All fills are rounded down to the nearest integer (which may be zero).
- Leveling – Remaining quantity from rounding during the Pro Rata step is distributed to participating orders. No order may receive more than one lot in this step.
- FIFO – Any remaining quantity is distributed to resting orders on a first in, first out basis (earlier timestamped orders receive fills before later timestamped orders).