The Deloitte Western Sydney Stock Exchange Index is compiled quarterly from publicly available information provided by the Australian Stock Exchange on pricing and market capitalisation of each Western Sydney listed company included in the BRW Top 500 Public Companies.

A company is included as a Western Sydney company where its registered office is in or around Western Sydney and/or a substantial portion of its operations are focused in Western Sydney. For the purposes of the Index, Western Sydney includes suburbs as far east of Parramatta as North Ryde, as far north as Castle Hill, west to Blacktown and south to Bankstown.

Monthly information on Western Sydney listed companies is extracted and each company assigned a weighting determined by its market capitalisation. The Index is then compiled by adding the weighted price movements of each company.