Yield Beta

Hi All,

I was going through the CFAI 2012 Mock AM and on question 8 there is a question which pertains to alter a bond portfolio value and modified duration. The question lists the bond futures with a modified duration and a yield beta.

I have see questions where the formula is as follows

Nf = [(Target MD - Portfolio MD) X (MV) / (Futures MD) (Futures Prices)] (Yield Beta)

However the answer does not incorporate the Yield Beta. Anyone have a definitive answer on when to incorporate a Yield Beta?


I think Kaplan said incorporate yield beta if they give you one, else just assume it’s 1.

I noticed that the yield Beta in that question is given and stated as 1.0. So whether you incorporate it or not, it would make no difference in this instance. That being said, on exam day I would personally incorporate it into my calculation just to show my complete and full work (out of an abundance of caution, maybe overkill… but oh well).

Agreed! It is just one extra number. If we list 1.0, I guess it does not take too much extra time :slight_smile:

Also, are you guys going to list the formulas first before we plug in the numbers? Or we can use the numbers directly during the exam?

I do not believe that the institute awards marks for writing out a formula using symbols… so I don’t see the point in wasting time doing that. I will still write out the formulae just with the numbers given to show method

Hi All,

You do not have to write out the formulas, it helps some people. Some of the harder formulas I really memorized hard and just write them down at the beginning of the exam so that I can access them easily later in the exam, sometimes you can blank later on, especially if you are in doubt on a few questions. This help me a lot on Level II, however that was much more formula intensive.

Regarding the problem, yes I do see the Yield Beta in the problem was just 1.0. However the answer key did not show the multiplication of the 1.0, so just wanted to make sure. I will multiply by the Yield Beta if given.


It’s almost always 1.0.