What is a Reversal Stop? Definition, Formula, and Example
A reversal stop is a dynamic order placement strategy where a trader simultaneously exits a losing position and enters a new position in the opposite direction at the same trigger price.
What is a Reversal Stop?
A reversal stop is an order type and risk management strategy where a trader exits an existing position and immediately enters a new position in the opposite direction when a specific price trigger is hit. Unlike a standard stop-loss order, which merely closes a position and moves the trader to cash, a reversal stop flips the position bias from long to short, or short to long, in a single execution. This is used by trend-following traders and systematic algorithms to ensure they are positioned in the direction of the prevailing momentum without experiencing execution lag.
How it is Calculated and Identified
A reversal stop is calculated by identifying a trend invalidation level. This level is often derived from technical indicators such as the Parabolic SAR, a moving average crossover, or a Donchian channel breakout. The order is placed as a stop-market or stop-limit order at the trigger price. The size of the new reversed position is calculated as:
New Position Size = Original Position Size + Reversed Position Size
If a trader is long 100 shares and wants to reverse to a 100-share short position, the broker must execute a 200-share sell order at the trigger price. The math requires sufficient buying power to handle the gross exposure of the flip.
Worked Example
A trader is long 100 shares of AAPL at $190. The trader sets a reversal stop at $185 based on a breakdown of the 50-day moving average. AAPL trades down to $185, triggering the order. The broker sells the 100 long shares to close the long position, and immediately sells 100 additional shares short at $185. The trader is now holding a 100-share short position with an average entry price of $185. If AAPL continues to drop to $175, the trader profits $10 per share on the new short position.
When Traders Use It
Traders use reversal stops in trending markets where price action exhibits clean, directional momentum. Trend-following systems, such as those built on the Supertrend indicator or Donchian channels, rely heavily on reversal stops to automate strategy execution. Day traders use them during momentum shifts, such as a failed breakout that immediately reverses into a breakdown. The order eliminates the psychological friction of manually closing a losing trade, waiting for confirmation, and then re-entering. It forces immediate participation in the new trend.
Limitations and Common Misconceptions
Reversal stops are highly vulnerable to whipsaw and false breakouts. In ranging markets, a reversal stop triggers repeatedly, generating cascading losses and frictional slippage costs. A common misconception is that reversal stops protect capital. They cap the loss on the initial position, but they immediately expose the trader to risk in the opposite direction. If the price triggers the stop and immediately reverses back, the trader loses on both the original position and the new reversed position. Additionally, short-selling via a reversal stop requires locate availability and margin privileges, which can fail during high short-interest environments.