ASX Grain Futures contracts are based on the Grain Trade Australia (GTA) No 2 Contract, otherwise known as a 'Track' contract.
GTA coordinates the annual assessment and publication of the GTA Location Differentials. It is important to note that they are not freight rates. They are an industry accepted measure by which Track contracts can be settled.
A ‘Track’ contract requires a commodity to be delivered up country within a certain specified price basing point (or port zone). The settlement value of this contract is calculated by subtracting the prevailing applicable location differential at the time of delivery specific for a tributary up country location from the 'Track' price.