This ProBuilder code snippet is designed to calculate round number levels in Forex trading, which are often considered psychological levels that can influence market behavior. The code determines the nearest upper and lower round numbers relative to the current price.

roundnumber = 25
pipclose=close/pipsize
for i = 1 to roundnumber DO
    if (pipclose+i) mod roundnumber = 0 THEN
        pipupper = round(pipclose+i)
        if pipupper mod roundnumber = 1 THEN
            pipupper = pipupper-1
        ENDIF
        break
    ENDIF
NEXT
for i = roundnumber downto 1 DO
    if (pipclose-i) mod roundnumber = 0 THEN
        piplower = round(pipclose-i)
        if piplower mod roundnumber = 1 THEN
            piplower = piplower-1
        ENDIF
        break
    ENDIF
NEXT
upper=pipupper*pipsize
lower=piplower*pipsize
return upper as "upper", lower as "lower"

The code snippet above performs the following steps:

• Initialization: Sets the roundnumber to 25, which is used as a base for calculating the round number levels. The pipclose variable is calculated by dividing the current close price by pipsize, normalizing the price to ‘pip’ units.
• Upper Round Number Calculation: A loop runs from 1 to roundnumber. It checks if adding each increment to pipclose results in a number that modulo roundnumber equals zero. If true, it rounds the result and checks if it needs adjustment to ensure it’s a proper round number. The loop breaks once a valid upper round number is found.
• Lower Round Number Calculation: Another loop runs from roundnumber down to 1. It performs a similar check as the upper calculation but subtracts the increment from pipclose. It also breaks once a valid lower round number is found.
• Result Assignment: The calculated upper and lower round numbers are then scaled back to the original price units by multiplying them by pipsize. The function returns these values labeled as “upper” and “lower”.

This code is useful for traders who consider psychological price levels in their trading strategies, providing a way to automatically identify these levels based on the current market price.