An expanding economy, new technologies, and changing consumer preferences provided growth opportunities for firms in interwar Australia. This period saw an increase in the number of large-scale firms in mining, manufacturing, and a wide range of service industries. Firms unable to rely solely on retained earnings to fund expansion turned to the domestic stock exchanges. A new data set of capital raisings constructed from reports of prospectuses published in the financial press forms the basis for the conclusion that many firms used substantial injections of equity finance to augment internally generated sources of funds. That they were able to do so indicates a strong increase in the capacity of local stock exchanges and a greater willingness of individuals to hold part of their wealth in transferable securities.