This code snippet is designed to calculate the percentage spread between the highest and lowest moving averages on a chart and track the historical maximum and minimum values of this spread. It uses three different types of moving averages: two exponential and one simple moving average.

a = exponentialaverage[6]
b = average[10]
c = exponentialaverage[20]
upper = max(max(a,b),c)
lower = min(min(a,b),c)
d = ((upper - lower) / close) *100

if c > 0 then
    if minapart = 0 then
        minapart = d
    endif
    maxapart = max(d,maxapart)
    minapart = min(d,minapart)
endif

return d as "% MA Zone", maxapart as "max MA spread", minapart as "min MA spread"

Explanation of the Code:

• Initialization of Moving Averages: The variables a, b, and c are assigned the values of an exponential moving average over 6 periods, a simple moving average over 10 periods, and another exponential moving average over 20 periods, respectively.
• Calculating Upper and Lower Bounds: The upper variable finds the maximum value among the three averages, and the lower variable finds the minimum value among them.
• Spread Calculation: The variable d calculates the percentage difference between the upper and lower moving averages relative to the current closing price.
• Tracking Maximum and Minimum Spreads: The code checks if the third moving average c is greater than zero to ensure valid data. It initializes minapart with the value of d if it’s the first calculation (i.e., minapart is zero). It then updates maxapart and minapart to store the maximum and minimum values of d observed historically.
• Output: The function returns the current spread percentage as “% MA Zone”, and the historical maximum and minimum spreads as “max MA spread” and “min MA spread”, respectively.

This snippet is useful for analyzing the variability and convergence/divergence of different moving averages over time, providing insights into market trends and volatility.