This code snippet demonstrates how to implement three different types of trailing stop strategies in ProBuilder language. Trailing stops are dynamic stop orders that adjust as the market price moves, helping to protect profits while allowing a trade to remain open as long as the price is moving favorably.

//%trailing stop function
trailingPercent = tst
stepPercent = st
if onmarket then
    trailingstart = tradeprice(1)*(trailingpercent/100) //trailing will start @trailingstart points profit
    trailingstep = tradeprice(1)*(stepPercent/100) //% step to move the stoploss
endif
//reset the stoploss value
IF NOT ONMARKET THEN newSL=0 ENDIF
//manage long positions
IF LONGONMARKET THEN
    //first move (breakeven)
    IF newSL=0 AND close-tradeprice(1)>=trailingstart THEN newSL = tradeprice(1)+trailingstep ENDIF
    //next moves
    IF newSL>0 AND close-newSL>trailingstep THEN newSL = newSL+trailingstep ENDIF
ENDIF
//manage short positions
IF SHORTONMARKET THEN
    //first move (breakeven)
    IF newSL=0 AND tradeprice(1)-close>=trailingstart THEN newSL = tradeprice(1)-trailingstep ENDIF
    //next moves
    IF newSL>0 AND newSL-close>trailingstep THEN newSL = newSL-trailingstep ENDIF
ENDIF
//stop order to exit the positions
IF newSL>0 THEN
    SELL AT newSL STOP
    EXITSHORT AT newSL STOP
ENDIF

Explanation of the Code:

• The code starts by defining two percentage values: trailingPercent and stepPercent, which determine the initial point to start the trailing stop and the step size to move the stop loss, respectively.
• It checks if the market is entered (onmarket). If true, it calculates the trailingstart and trailingstep based on the trade price and the defined percentages.
• If the market is not entered, it resets the stop loss value (newSL) to zero.
• For long positions, the code first checks if the stop loss is not set (newSL=0) and the profit has reached the trailingstart. If true, it sets the stop loss to the trade price plus the trailing step. It then adjusts the stop loss further if the price continues to rise.
• For short positions, similar logic is applied but in the opposite direction, adjusting the stop loss down as the price falls.
• Finally, if a new stop loss (newSL) is set, the code places a stop order to exit the position at the new stop loss level for both long and short positions.

This snippet is a practical example of how to manage risk dynamically in trading strategies using ProBuilder language, focusing on trailing stops to lock in profits while allowing room for further gains.