Order Management System

For most retail orders in liquid ASX stocks, limit orders offer better control with minimal delay. Set limits at or slightly better than current market prices for quick fills. Use market orders only when immediate execution is critical and you accept potential slippage.

Your broker platform shows order status: Working (on exchange), Partially Filled (some executed), Filled (complete), or Cancelled. You will also receive a contract note (trade confirmation) via email for filled orders. Always verify fills before assuming execution.

Day orders automatically expire/cancel at market close if unfilled. GTC (Good Till Cancelled) orders persist to the next trading day. Check your order's time-in-force setting. Most retail orders default to Day orders.

Yes, while an order is working (not yet filled), you can modify price or quantity, or cancel entirely. Once filled (even partially for that portion), that execution is final. Check your broker platform for modify/cancel options on working orders.

Use limit orders instead of market orders. Consider breaking large orders into smaller pieces over time. Trade during liquid hours (avoiding first and last 30 minutes). For very large orders relative to daily volume, consider algorithmic execution or working the order over multiple days.

For routine orders, 10:30 AM - 3:30 PM AEST typically offers best execution with tighter spreads and stable prices. Avoid opening (10:00-10:30 AM) unless you need to participate in the open. Closing can be busy but volatile. Match timing to urgency.

Define a policy: For example, if 75%+ fills, let the rest work. If less than 25% fills after 30 minutes, cancel and reassess. Small odd-lot remainders might not be worth the brokerage to fill. Consistency prevents ad-hoc decisions.

GTC orders are useful for standing orders at target prices (e.g., limit buy at support level). However, review GTC orders regularly - market conditions change, and an old order might fill at a no-longer-appropriate time. Many traders prefer fresh daily orders.

VWAP execution splits orders across the day proportional to typical volume pattern. Calculate historical volume distribution by time period. Submit slices matching that pattern. Compare total fill to day's VWAP. Institutions use algorithmic tools; retail can approximate manually for large orders.

Use hidden orders when your order size might move the market if displayed. If your order represents more than 10-20% of typical daily volume, consider Centre Point or iceberg orders. The trade-off is potentially slower execution since you are not in the visible order book.

Start with Interactive Brokers' TWS API (most comprehensive for Australian access). Learn the API documentation. Implement paper trading first. Build in pre-trade validation, order submission, status monitoring, and execution logging. Extensive testing before live trading is essential.

Compare fill to arrival price (price when you decided to trade), VWAP, and close. Calculate explicit costs (brokerage). Calculate implicit costs (half-spread + impact + timing drift). Track by stock, order size, time of day, order type. Identify patterns and improvement opportunities.