Backtest result is different from the real trading

 
Is it possible to have a MT4 EA with +700% of gain in 1 year on a live real account and when I made a backtest for the same period I obtain -3% (with the same settings)? The seller of this EA tells me:  ​not all backtests are accurate. What is your opinion?
 
8tango: Is it possible to have a MT4 EA with +700% of gain in 1 year on a live real account and when I made a backtest for the same period I obtain -3% (with the same settings)? The seller of this EA tells me:  ​not all backtests are accurate. What is your opinion?

Unable to give a definitive answer without more details. However, if this is someone trying to sell you an EA, you should not accept things at face value. You need to research the situation more.

 
Fernando Carreiro #:

Unable to give a definitive answer without more details. However, if this is someone trying to sell you an EA, you should not accept things at face value. You need to research the situation more.

I bought this EA but I have 30 days as money back, for the moment I test it on a demo account.

Which more details do you need to give me a realistic opinion?

 
8tango #: I bought this EA but I have 30 days as money back, for the moment I test it on a demo account. Which more details do you need to give me a realistic opinion?

Since you don't have the source code and discussions about 3rd party products are not allowed on the forum, there is not much we can do for you.

However, 700% gain in a year is far-fetched for properly risk controlled trading. If it looks too good to be true, then it probably is fake.