It’s a great pleasure for me to use TRADINGVIEW platform. I am greatly thankful to the pinescript LEGENDS ( @filbfilb , @glaz, @JayRogers, @QuantNomad , @Bjorgum, @LonesomeTheBlue and many more) who helped in understanding pinescript language (and helping me where ever I got struck in script).
Here is my my little contribution to community: BTC Holy Grail Level.

This level (PURPLE LINE) has been tested by BTC 3 times (years) in history and has never got failed.
1st time: On 8th June 2012, HIGH was made ($31.91). Then it retraced back to Holy Grail Level at $4.12 (on 16th Feb 2012) which was 87.09% correction.

2nd time: On 29th November 2013, HIGH was made ($1242). Then it retraced back to Holy Grail Level at $176.78 (twice a year on 14th JAN 2015 and 18th Aug 2015) which was 85.77% correction.

3rd time: On 17th Dec 2017, HIGH was made ($19804.25). Then it retraced back to Holy Grail Level at $3823.43 (on 24th Nov 2018) which was 80.69% correction.

CURRENT SCENARIO
4th time possibility: On 8th Nov 2021, HIGH was made ($68997.75). BTC Holy Grail Level is at $15914.46 right now which is 76.93% correction.

THANKS.