Isn’t first differencing necessary if a formula is a random walk? Now I’m being told that if it is ‘truly random walk’ it is covariance stationary and no further manipulation is needed?
CFAI Morning 2011 exam
Isn’t first differencing necessary if a formula is a random walk? Now I’m being told that if it is ‘truly random walk’ it is covariance stationary and no further manipulation is needed?
CFAI Morning 2011 exam