I have estimated two different time series (A and B) using daily data, and the average returns of each of them are insignificant. However, once I construct a third time series using the difference between A and B (A-B). The average returns of A-B are significant. How to interpret these results? Can I say that?

"As both the A and B strategies do not generate positive returns; therefore, difference between A and B at least indicate that the the effect of A tends to be stronger than the effect of B.

Thank you very much for your time, really appreciated.

Kind Regards,

Mac