Stop Order

What Is a Stop Order?

A stop order (sometimes called a stop-market order) is a conditional order that remains dormant until a specified trigger price is reached. Once the trigger price is hit, the stop order converts into a market order and executes at the best available price. This mechanism makes stop orders the primary tool for automated risk management and breakout entries.

The trigger price is called the stop price. For a sell stop (the most common type, used as a stop loss on long positions), the stop price is set below the current market price. For a buy stop (used for breakout entries or stop losses on short positions), the stop price is set above the current market price.

How Stop Orders Are Used

Stop-loss protection is the most widespread application. A trader who buys a stock at $100 might place a sell stop at $95, limiting their potential loss to $5 per share. If the stock drops to $95, the stop triggers, and the position is sold at the market price. This automatic protection ensures the trader does not have to monitor the position constantly.

Breakout entries use buy stops above resistance or sell stops below support. A buy stop at $52 on a stock trading at $50 with resistance at $51.50 will only trigger if price actually breaks above $52, ensuring the trader enters only if the breakout occurs.

Trailing stops are a dynamic variation where the stop price moves with the market. As a stock rises, the trailing stop rises with it, locking in profits. If the stock reverses, the trailing stop remains at its highest level and triggers if price drops to it.

Risks and Limitations

The most significant risk is gap slippage. Because a stop order becomes a market order upon triggering, the execution price can be significantly worse than the stop price if the market gaps past it. This is especially relevant for stocks that can gap on earnings, pre-market news, or over weekends.

In extremely volatile conditions, stop orders can also be triggered by brief intraday spikes (stop hunting) before the market reverses. This phenomenon has led some traders to use wider stops or mental stops (watching the price manually) rather than hard stop orders, though each approach has its own tradeoffs.