What is good today may not be for tomorrow?

Hi guys, I heard that if a strategy that works great for 1 - 2 years may suddenly not work and cause one to start piling losses with the same strategy?

Is it true? Has anyone experience this before?

you keep asking questions which is good, but my advise to you is devote yourself to :

1- study the structure of the market
2-macro economics
3- statistics
4- observe and draw your own conclusion
5- money management


and read posts of good traders here

1 fti technical analysis fallacy
2 crucial point (he has post in the reclying bin, find it)
3 hanover
4 pip trapper
5 chickey (sorry bad spelling)
6 custos
7 cloggie
8 dark star
9 look for quotes from the greats and see what they all have in common

Actually this depends on a strategy but:
- Most likely the strategy will not "stop earning suddenly". It can start trading with no profit "profit trades ~ losing trades" at this point I'd suggest to turn it off and go to demo account or better to backtesting software to re-design the strategy or create a new one.
- It is better to re-optimize the strategy from time to time (at least once per month) because the market is always changing and you need to be up to date

Thanks in advance Maestro, what software platform do you recommend for backtesting?