Order Types (Market, Limit, Stop)
Order types express your priority: do you care more about being filled, or about the price you pay?
Market orders say “fill me now” and sacrifice price certainty for execution certainty — you trade immediately at the best available prices.
Limit orders specify a worst acceptable price; they protect you from bad prices but may never execute if the market does not reach your limit.
Stop orders activate when a trigger level is hit, then behave like market or limit orders; they are often used as safety brakes to cut losses.
Control analogy: order choice is like choosing between fast but noisy control actions (market) versus slower, more precise ones (limit) under constraints.
This diagram shows a short price path over time with bid/ask band. Choose an order type to see when it fills and how much slippage vs mid you incur.
Market orders sit on the execution certainty end of the spectrum: you always trade now, but you pay the full spread and whatever the book offers in fast moves.
Limit orders move towards price control: you only trade if the market comes to you. Stops are about controlling risk; with gap risk on, you see how a stop-loss can trigger at one level and be filled much worse in a discontinuous market.
The highlighted corner shows where the chosen order type leans: market towards execution certainty, limit towards price control, and stop towards risk control. Real execution policies mix these, just like a controller trades off speed, overshoot, and robustness.