This thesis seeks to identify systematic differences in the order placement of institutional and retail traders in the Australian market. With institutions exhibiting a greater awareness of market conditions, this analysis facilitates the comparison of informed and uninformed
trading behaviour. Applying broker IDs as a proxy for trader type, the characteristics and the execution costs of institutional and retail orders are analysed to compare their order performance. Retail traders demand immediacy, accounting for a disproportionate volume of market orders and aggressive limit orders. Exposed to heightened execution risk, these traders also place a higher volume of limit orders behind the quoted spread. In comparison, institutional traders, concentrating order flow within the quoted spread. As passive investors, these traders exhibit a preference for limit orders priced at the best same side quote. Whilst institutional and retail traders exhibit distinct order placement strategies, no significant differences are observed in their order execution costs.