bollinger band scan

[ezrollin]

I want to find that all bars are within these bollingers throughout the whole 120 day period.
Instead of just "any bar is inside the bollingers within 120 days"
How do I change my scan script to the right format?

 

[traderLK]

I want to find that all bars are within these bollingers throughout the whole 120 day period.
Instead of just "any bar is inside the bollingers within 120 days"
How do I change my scan script to the right format?

Hi ezrollin,

I thought this would be fairly straightforward, but boy was I wrong... all my initial ideas had fatal flaws until I incorporated some advice I got from Halcyonguy a while back about using a sum of conditions.

This script below plots signals whenever the close has been between the upper and lower Bollinger bands for all of the last <length> bars. I started with 120 bars as mentioned above, but there just weren't any signals in the markets and timeframes I checked. Even with 50 bars the signals were hard to find. I ultimately set the default at 30 price bars. This length can be adjusted in the inputs.

I've attached a daily chart showing the signals in NVDA when length is set to 30.

# Bollinger_All_In
# Question from ezrollin on 2-24-24
# Plots signal when the close has been inside the BB bands for the past <length> bars

input price = close;
input BBlength = 20;
input Num_Dev_Dn = -2.0;
input Num_Dev_up = 2.0;
input averageType = AverageType.SIMPLE;
input length = 30;

def sDev = stdev(data = price, length = BBlength);

def MidLine = MovingAverage(averageType, data = price, length = BBlength);
def LowerBand = MidLine + num_Dev_Dn * sDev;
def UpperBand = MidLine + num_Dev_Up * sDev;

def cond1 = close < UpperBand and close > LowerBand;
def cond2 = sum(cond1, length);

plot AllRinside = if cond2 == length then 1 else 0;

AllRinside.SetPaintingStrategy(PaintingStrategy.BOOLEAN_ARROW_UP);
AllRinside.SetDefaultColor(Color.RED);
AllRinside.SetLineWeight(4);