@nischansr I am failing to understand why you are mixing two completely different things.
One is using rolling returns as a measure of comparison between two financial instruments. And the second how you plan to invest in those two instruments.
If you plan to use sip then you need to use that to stimulate return for any period - be it trailing return or rolling return. Importance of that is what op had shown in his calculation. And if you do sip you need to use xirr. I really don't care what you use for comparison but you have to consider what you are planning do.
One is using rolling returns as a measure of comparison between two financial instruments. And the second how you plan to invest in those two instruments.
If you plan to use sip then you need to use that to stimulate return for any period - be it trailing return or rolling return. Importance of that is what op had shown in his calculation. And if you do sip you need to use xirr. I really don't care what you use for comparison but you have to consider what you are planning do.