in really clear about the last setence of the first para (on pg56, vol3) does it mean the “portfolio duration” - really think the book is not properly written!
Can’t find what you are referring to! - sticky
it’s actually from Vol4…pls see the last sentence below… without proper hedging to offset the changes in the duration of mortgage securities caused by interest rate movements, the portoflio’s duration would drift adversely from its target duration. “in other words, the portfolio would be shorter than desired when interest rates decline and longer than desired when interest rise.” my understanding is the portfolio’s duration would decline when interest rate decline due to faster prepayments… “portfolio” in the last sentence should be “portfolio’s duration”
— “portfolio” in the last sentence should be “portfolio’s duration” Agree. But I think that doesn’t make much difference from the original text 
Portfolio A is shorter than portfolio B (which means “in terms of duration”) - sticky
wow! not familiar with the term: Port A is shorter than Part B… can get what the author mean, but just at that point, it’s way too simplified comparing to the text prior to that! maybe the author was frustrated when he was writing the stuff… hehe thanks sticky!