Market vs. Limit Orders for Options

Limit Orders

A limit order executes only if option contracts are available at your specified limit price or better.

  • For buys: executes at your limit price or lower.

  • For sells: executes at your limit price or higher.

  • By default, most limit orders are Day orders, which expire at the end of the trading day if not filled.

  • If you select Good ‘Til Canceled (GTC), the order will remain active for up to 90 days (or until the option contract expires or you manually cancel it).

Key points:

  • Provides price protection but does not guarantee execution.

  • Useful when you want control over the price you pay or receive.

  • In low-volume options, it’s possible your order may never fill if the market doesn’t reach your limit.

Market Orders

A market order seeks immediate execution at the best available price.

Key points:

  • Prioritizes execution, but does not guarantee execution or price.

  • The final fill price can differ from the last quoted price, especially in volatile or illiquid options.

Stop and Stop-Limit Orders

  • Stop Orders: Become market orders once a trigger price is reached.

  • Stop-Limit Orders: Become limit orders at a specified price once the trigger price is hit.

  • These order types may be used to manage risk on existing option positions.

Multi-Leg Orders

A multi-leg order combines two or more option legs into a single strategy (e.g., straddles or strangles).

  • Can be placed as a net debit (you pay) or net credit (you receive).

  • Market and limit are both supported by multi-leg orders.

Buying Power for Options

Buying power represents how much you can use to open new positions. For options:

  • Long options (buying calls or puts): require you to pay the full premium upfront.

  • Short options (selling to open): collateral requirements depend on the strategy and applicable account requirements.

  • If you sell a covered call, your underlying stock is reserved as collateral, reducing your available buying power for that position.

  • If you sell a cash-secured put (CSP), cash equal to the strike price × 100 per contract is reserved as collateral and unavailable for other trades until the position is closed or expires.