I just wanted to confirm that you use the yield beta only when you are using futures (like treasuries) to hedge a portfolio of corporates? If the formula to change modified duration is: [MDx - MDx-1/MDf] * (portfolio value/futures), —> you only then multiply by the yield beta if these are different, correct? I could see CFAI getting tricky on this one.
There’s a massive thread regarding this that’s got all the info you need.