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Order types

#trading

Order types are the rules that control how a trade gets placed and filled. Four cover 90% of real trading:

  • Market — fill immediately at whatever price is available. Fast, but pays slippage.
  • Limit — only fill at your specified price or better. No slippage, but may never execute.
  • Stop — dormant until price crosses a trigger, then becomes a market order. Used for stop-losses.
  • Stop-limit — same trigger, but becomes a limit order (more control, more risk of not filling).

On top of those, time-in-force flags: IOC (fill what you can immediately, cancel the rest), FOK (fill the whole thing now or cancel entirely), GTC (good till cancelled). Every real trading strategy is just a composition of these primitives.