This script is based on the Gann's 50% Retracement rule.
First, the ATH (All Time High) and ATL (All Time Low) are calculated; then, the 50% retracement level is found.
With this 50% level, we'll calculate the maximum price entry to keep a ROI which is set in the parameters.
For exemple, I only want to buy assets which can make a x16 before the 50% retracement...
