I have a MF portfolio which I created to achieve a certain goal in long term. I check the performance of the funds once in a year. In last analysis i found one fund underperforming (below than category average). So i want to switch to a different fund of the same category. But After i switch over, what happens to the sum i invested in the previous fund ? Should I redeem the amount and invest in a good plan lumpsum or keep the amount as it is ?