Map of Toowong on Tier sizes refer to how many shares are able to be SOESeligible in a particular order. The three tier sizes currently are 200, 500, and 1,000. This means that if a stock has a tier size of 200, then a trader cannot enter a SOES order for more than 200 shares. If the tier size is 1,000, then a trader can enter an amount up to 1,000 shares. SOES provides instant executions against Market Maker participants at specific price levels. This is the advantage for the active trader when wanting to execute an order in a fast and efficient manner. The order can be a market or limit order. Map of Toowong 2016.