So looking at the CFAI material (pg. 475-478 in Volume 4 for 2019) as well as the Kaplan Schweser material (pg. 70-74 in Book 4) and I’m trying to make sense of this new material added…

I believe I understand the Contribution of Asset A to Absolute Portfolio Variance (CVa) to be CVa = Wa x Cov (a, p), where we first find the Covariance of Returns between Asset A and the portfolio by calculating, for example, (Wa x Cova,a) + (Wb x Cova,b) + (Wc x Cova,c) and then to find A’s contribution to Total Portfolio Variance we just multiply Wa x the summation of what we just found.

Can someone explain Contribution of Factor A to Absolute Portfolio Variance and Contribution of Asset A to *Relative* portfolio variance in a detailed, step-by-step process?