Unlike electricity, the gas market in Australia is split into different "hubs" with different rules, primarily the Victorian Declared Wholesale Gas Market (DWGM) and the Short Term Trading Markets (STTM) in other states.
The Victorian market is unique because it operates on a "market carriage" model. AEMO manages the transmission system directly, and market participants bid into a daily pool to inject or withdraw gas. Prices are set daily at 6:00 AM, 10:00 AM, 2:00 PM, 6:00 PM, and 10:00 PM.
These hubs operate as Short Term Trading Markets (STTM). They run on a "contract carriage" model, where users must book pipeline capacity separately. The STTM sets a daily ex-ante price for gas delivered to the hub.
Since 2015, the East Coast gas market has been linked to international LNG prices due to export terminals in Queensland. This means local prices are often influenced by global demand rather than just local supply.