EA performs really well in 2020, but not 2019

[Joao Marcel Fernandes Pereira]

Hi everyone. I want to ask you if it's possible for my EA to perform really well from March 2020 until now, and when I proceed to test it out in 2019, it basically doesn't perform even close to that. Risking 3% per trade in 2020, you would get ~15-20%, and in 2019 it would loose money actually.

Is it possible for a day trading strategy on the 15tf, to perform really well in the past 6 months and then do this? Or I can't really trust on the strategy tester results? 

[William Roeder]

Of course it's possible, the market never repeats the same.

Or you over optimized it for a specific period.

[Joao Marcel Fernandes Pereira]

William Roeder:

Of course it's possible, the market never repeats the same.

Or you over optimized it for a specific period.

I didn't optimized it for this year at all. 

I just can't understand why a day trading strategy that places basically a trade everyday, can work so good in April-September 2020, but before that pretty much fail almost every month. Guess I'm back to the drawing board.

Thanks for the reply.

[[Deleted]]

jota9913:

I didn't optimized it for this year at all. 

I just can't understand why a day trading strategy that places basically a trade everyday, can work so good in April-September 2020, but before that pretty much fail almost every month. Guess I'm back to the drawing board.

Thanks for the reply.

This year seems a little odd. An unoptimized EA of mine did the same thing. One thing is certain, a random strategy can perform well for a limited time (out of luck). But a well-tested strategy can adjust to market dynamics. 

The drawing-board it is.