Reading 24, Section 4.1.2 - Bottom up relative value analysis

In this section CFA book says “If investor plans to hold a bond to maturity, the change in credit spread throughout the holding period is effectively zero”. Can someone please explain this statement?

If you hold the bond to maturity then the bond’s YTM is the original YTM (I’m ignoring reinvestment risk for simplicity), which includes the original credit spread.

Got it. Thanks!

My pleasure.