Independent solution

How to solve this Duration and Convexity question

Setup

Setup

Use price convexity defined as the second yield derivative divided by price.

CX=50(51)1.052=2312.93C_X=\frac{50(51)}{1.05^2}=2312.93

Model

Model

A level perpetuity has convexity two divided by yield squared, while a long zero uses its maturity factors.

CY=20.052=800C_Y=\frac{2}{0.05^2}=800

Compute

Compute

Replacing yield by yield minus growth gives the growing perpetuity's larger convexity.

CZ=2(0.050.03)2=5000C_Z=\frac{2}{(0.05-0.03)^2}=5000

Answer

Answer

The order from lowest to highest is y, x, z, corresponding to choice B.

y<x<z(B)\boxed{y<x<z\quad\text{(B)}}