I hear things like "if too many people know your edge it ceases to be an edge." So, say you've discovered a system that works. Let's say it's pretty TA based, but there's some discretion involved, too. How long would this system work, on average? Or can you not answer a question like that? I just wonder, what if someone quit their job cuz they had an "edge" only to find that their "edge" stops working in 2 years, or 6 months...
Ive found "dead" systems that worked for 6 years but no longer. Ive found systems that only worked during the 2000 NAZ boom for 2-3 years. Ive found systems that work as far back as I can test, about 20 years and are still going strong. No way to predict how long they will work though. Thats why you need multiple systems. Depending on just one for a living is pretyy scary.
From what ive seen systems that are based on setups and a little bit of discretion last much much longer than those that depend strictly on "signals" to initiate trades.