On both entry windows there is an action button "CLOSE" which will close a position or a strategy depending on what mouse button is pressed.

When a position or strategy is closed, NinjaTrader goes through the following process:

Assume we are long the SP Emini contract at an entry price of 1000.

1. Identifies any working sell limit orders
2. Cancel all other orders
3. Modifies the price of the identified working sell limit orders below the market so that they get filled instantly
4. Submit a sell market order if necessary for any left over contracts that are not covered by the identified working sell limit orders

The exception are currencies (FOREX) where all working orders are cancelled and then a market order is submitted to close the position.

Why not just submit a market order?

A lot of traders consume near 100% of their available margin. For example, you may have 1 contract position with one stop and target that consumes 90% of your margin. If you close a position by submitting a market order, the market order will get rejected due to insufficient funds and therefore cause grief if getting out of the position is critical.

The NinjaTrader approach offers several benefits:

• Modifying existing limit orders avoids the potential problem of breaching your account margin limitations when closing a position
• With some brokers, modifying existing orders is more efficient than submitting new orders by up to 500 milliseconds
• Cancellation of non essential orders unlocks available margin that could potentially get consumed if a market order is required to close out any remaining contracts that are not covered by existing limit orders

This approach essentially guarantees the most efficient way to exit a position.