This ProBuilder code snippet is designed to calculate and visualize the maximum drawdown and the current drawdown for a financial market based on historical data. The maximum drawdown is a measure of the largest single drop from peak to trough in the value of a portfolio, before a new peak is achieved. This is useful for assessing the risk of a trading strategy.

// Biggest Draw Down Analysis Tool
//By Vonasi
//13 June 2018
//Percentage = 0
IF High > lastHigh then
    LowestLow = low
    LastHigh = high
ENDIF
IF High < LastHigh then
    LowestLow = Min(LowestLow,low)
    DrawDown = LastHigh - LowestLow
    BiggestDD = Max(BiggestDD, DrawDown)
endif
IF Percentage then
    DrawDownRes = (DrawDown/close)*100
    BiggestDDRes = (BiggestDD/close)*100
ELSE
    DrawDownRes = DrawDown
    BiggestDDRes = BiggestDD
ENDIF
return -DrawDownRes coloured(0,0,255) as "Draw Down", -BiggestDDRes coloured(128,0,0) as "Biggest Draw Down"

The code operates by tracking the highest and lowest points reached by the market and calculating the drawdowns from these points. Here's a step-by-step breakdown:

• Initialization: The variable Percentage is set to 0 to indicate that results are to be displayed as absolute values rather than percentages.
• Tracking New Highs: If the current high is greater than the last recorded high (lastHigh), the script updates LastHigh to the current high and sets LowestLow to the current low.
• Calculating Drawdown: If the current high is less than LastHigh, the script calculates the drawdown by finding the minimum of LowestLow and the current low, and then subtracts this value from LastHigh.
• Updating Maximum Drawdown: The maximum drawdown (BiggestDD) is updated by taking the maximum of itself and the newly calculated drawdown.
• Result Calculation: Depending on whether Percentage is true, drawdown results are either calculated as a percentage of the closing price or as absolute values.
• Output: The drawdown and maximum drawdown are returned as negative values for visualization purposes, with specific colors assigned to each for distinction.

This snippet is particularly useful for traders and analysts looking to understand the historical volatility and risk associated with a market or strategy.