Log return of stock price
So log(P(t)) and log(P(t-1)) share t-1 past returns, which means they will be highly correlated. Random Walk Model for Stock Prices. • If changes in (log) prices hi there, How do i compute monthly stock returns using monthly end prices in sas. by stock;. prev_open=lag(open);. return=log(open/prev_open);. if first.stock So the calculation for yearly stock return is log(36.51/32.13) where denotes price on year . This needs to be done for every year of each firm(ID).