Spread Risk on Mortgage Securities mortgage, confusion, allocation, buying

jbaldyga

Just to clear some confusion,

In book 4 p. 168, my understanding is a portfolio manager doesn't seek to hedge spread risk but to capture value through spread changes that is why it is beneficial to increase the allocation to mortgage securities when spreads are high (buying low) and decreasing allocation when spreads narrow (selling high). Is this correct? I find the fixed income readings not written clearly.