A trailing stop is a dynamic stop-loss order that automatically adjusts as the price moves in your favor. Unlike a fixed stop-loss that stays at one price level, a trailing stop follows the price upward (for long positions) or downward (for short positions), locking in profits while still allowing the trade to run. The stop only moves in the direction of your trade and never reverses, ensuring that your maximum loss is limited to the trail distance from the highest (or lowest) price reached.

Trailing stops are widely used by swing traders and trend followers who want to capture as much of a price move as possible without manually adjusting their stop-loss orders. They are particularly effective in trending markets where prices move significantly in one direction over time, allowing traders to ride the trend while protecting against sudden reversals.

When you set a percentage-based trailing stop, the stop price is calculated as a fixed percentage below the current market price. As the price rises, the stop price rises with it, maintaining the same percentage distance. For example, with a 2% trailing stop and an entry at $100, your initial stop would be at $98. If the price rises to $110, your stop automatically moves up to $107.80 (2% below $110).

A fixed-amount trailing stop works similarly but uses a specific dollar or pip amount instead of a percentage. For instance, a $5 trailing stop on a $100 entry starts at $95. When price reaches $115, the stop moves to $110. The key advantage is that the stop never moves backward, so once profits are locked in, they are protected regardless of subsequent price action.

The ideal trail distance depends on the instrument's volatility and your trading style. Too tight a trailing stop may result in being stopped out by normal price fluctuations before the trend continues. Too wide a trailing stop may give back too much profit during reversals. A common approach is to use the Average True Range (ATR) indicator as a guide -- setting the trail at 1.5x to 3x the ATR value.

Scalpers and day traders typically use tighter trailing stops (0.5-2%) to protect quick profits, while swing traders and position traders may use wider trails (3-10%) to allow for larger price swings. Consider backtesting different trail distances on historical data to find the optimal setting for your specific trading strategy and the instruments you trade.

Trailing stops are not guaranteed to execute at the exact stop price, especially during gaps or periods of extreme volatility. Slippage can occur, resulting in a fill price worse than the stop level. In fast-moving markets, prices may gap past your trailing stop, leading to larger losses than anticipated. Additionally, trailing stops work best in trending markets and may result in frequent stop-outs in choppy, range-bound conditions.

Consider combining trailing stops with other risk management tools such as position sizing and portfolio diversification. Some traders use a hybrid approach, starting with a fixed stop-loss and switching to a trailing stop once the trade has moved sufficiently into profit. This can help avoid being stopped out during the initial stages of a trade while still protecting profits as the position develops.