Does anyone here know what kind of questions to expect, how do they tend to build their fixed income portfolios ?
Hmm, was this covered in L2 or L3 of the curriculum?
Match the cash flows, match the duration, etc…
They will ask you a lot about duration, valuing liabilities, and how interest rate changes affect present value of assets/liabilities. How do you immunize a liability? They will also likely ask how liabilities are valued, and perhaps relevant regulations. What liability are they managing to? Insurance? Banks? DB Pensions? In practice LDI is different for all of these due to regulations and challenges unique to each field.
For pensions and insurance, actuairies provide liability schedules. Liabilities are treated as zero coupon bonds maturing at the liability date, then this series of liabilities is discounted to arrive at a present value, yield, and duration. You want to construct a portfolio that resembles these risk characteristics.
As an example, in the US, corporate pension liabilities are discounted using highly rated corporate bond yields for accounting purposes. Therefore to immunize the plan funded status against interest rate and credit spread changes, portfolios are typically duration matched corporate bond portfolios with an average credit rating around Aa-A. As interest rates and credit spreads change, the asset market value should move with the present value of the liabilities.
There are some limitations in the corporate bond market (lack of supply in certain maturity buckets and lack of Aa rated bonds) that make blending lower investment grade corporates and governments a more feasable solution. Because of the liquidity in treasuries, its significantly easier to use them to cash flow match or fill in key rate duration buckets that are mismatched.
Some managers use Treasury futures or swaps to match key rate durations as closely as possible. For liability durations longer than 14 or so, its generally necessary to buy 30 year futures in order to extend duration.
If its a junior level position I would just focus on the basics. Some of this is covered in L3 fixed income portfolio management material.
No problem man, glad I could help!