::
The following question:
Corp. bond s.a pay
N=8 years @5.75 coupon is priced at 108.32. Duration: 6.4; Convexity: 0.5. Credit spread narrows with 75 basis points. Estimate return impact with/without convexity adjustment.
So without convexity is simple: -Duration*change in spread = -6.4*-0.0075 = 4.8%
I don’t get the logic with convex. adjustment.
-duration*change in spread + 1/2 convexity*(change in spread)^2
-6.4*-0.0075 + 1/2 (50) *(-0.0075)^2 = 4.94%
How did we get the convexity from 0.5 to 50? What’s the reasoning behind this adjustment. Help would be appreciated 🙂