Calculate and shift returns in dataframe

[nirgrahamuk]

This post doesnt seem a long way from your previous which had proposed solutions that you didnt to

Calculate returns

Hi! I have a dataframe, like this: isin Year Month MV P RI VA MNEM 1 BMG0539N1020 2011 12 804.00 20.10 92.80 2888.1 N:AOD 2 BMG0539N1020 2012 12 1148.00 28.70 132.50 13.5 N:AOD 3 BMG067231032 2014 12 3598.35 100.91 90.40 406557.6 N:AVAN . . With 4691 observations of annual stock price data (545 companies/isin, with various length of each observation). The observations start and end at different time intervals, some companies have annual data from 1980-2020, and some might have data for 2010-2015 etc. My problem is: I need to calculate the returns for each company/isin from RI. -> create a c…