Since Markets change over time, consequently a Trading System that worked well more than 20 years ago, must be adapted to current Markets. It is therefore necessary to use the methods of the professionals, such as Andrea Unger, Kevin Davey, etc., then apply a T.S. in a group of stocks (12-15 stocks with different characteristics, some trendfollowing and some mean-reverting), and with various time frames: 15 minutes, 30 minutes, 1 hour, etc...up to multiday; this method is well explained in the book: Trading System that Work by Thomas Stridsman. Only in this way will it be possible to identify on which Markets (Stocks, Index, Commodities, etc...) and which time frames the best results will be obtained; moreover, in addition to the traditional technique, it is often necessary to add filters to improve the various parameters. An example, in this Unger Academy video, in addition to using the classic Donchian Channel (in this case only long with the addition of a stop loss and a profit target), the equity line and various values are improved by adding a filter based on a simple pattern (there is code in easylanguage in the video):
%% SOUNDS like a 10 day stop loss, in that example ; the markets I trade + invest ,would not want to limit a profit to 10days. NOT likely any trend trader would limit a profit to 10 days; but if, stock-ETFs market, SEPT, may not want it 10 days LOL. Hope this helps, it helps me