Bond index fund

Not every fixed income investor wants a manager making calls on interest rates and credit. Some simply want to own "the bond market", or a defined slice of it, as cheaply as possible.

A bond index fund does that. The manager does not choose which bonds to buy based on a view. Instead, the portfolio copies a chosen benchmark index — the same securities, in the same, or nearly the same, proportions — so the fund's return simply tracks the index's return, up or down.

Section 19.2.2 gives four reasons a portfolio adopts bond indexing:

• Portfolio mandate. An investor — the workbook's own example is a global endowment fund manager who has decided to put 5% of the endowment into the Indian fixed income market — wants exposure to a benchmark, not manager discretion, and can engage a local partner to replicate it.
• Management fee. Indexing needs far less decision-making than active management, so the fee for running it is small.
• Ease of replication. The benchmark's own construction rules already handle liquidity, size, weight, issuer and credit-rating screening, and the index's own periodic rebalancing takes care of inclusions and exclusions — removing that burden from the portfolio manager.
• Availability of choice. India has many bond indices to choose from — sovereign bond indices, corporate bond indices, long-duration G-Sec indices, commercial paper indices, and indices sliced by maturity, duration, credit rating or issuer category — so a mandate can be matched closely to an investor's need, including by combining more than one index in a stated proportion.

The workbook also notes that liquidity risk in the underlying bonds can be mitigated by wrapping the strategy in an exchange-traded fund structure.

Illustrative figures, following the workbook's own example. A global endowment fund with total assets of US$2 billion decides to place 5% — about Rs 830 crore at Rs 83/US$ — into the Indian fixed income market, purely to gain India exposure as an asset class, not to bet on individual issuers.

It engages a Mumbai-based portfolio manager to run a bond index fund benchmarked to a broad Indian corporate bond index. The manager's job is not to forecast which bonds will outperform — it is to hold the index's constituents in the index's weights, rebalancing only when the index itself is rebalanced or when the Rs 830 crore sees inflows or outflows.

Because there is no active credit or duration call to make, the manager's fee on this mandate runs at roughly 0.15% p.a., against 0.75%–1% p.a. typically charged for an actively managed fixed income mandate of the same size — the saving the workbook attributes to indexing needing "no decision making or transactions" beyond tracking the benchmark.

Chapter 19, section 19.2.2 (Bond Index Funds), sits between Buy and Hold and Immunization as the second of the three passive fixed-income strategies. Expect a question on the four reasons for adopting bond indexing, and one applying the workbook's own global-endowment example.

• Indexing is passive but not identical to buy and hold. A bond index fund trades whenever the benchmark is rebalanced; buy and hold trades only at maturity.
• The manager's job shifts from picking bonds to picking (and then mirroring) the right benchmark — benchmark selection is itself a skill, even though security selection is not.
• Ease of replication comes from the index provider's own construction rules, not from the portfolio manager designing screening criteria independently.
• Bond index funds are not automatically liquid — the workbook notes that liquidity risk in the underlying bonds is a real concern, mitigated (not eliminated) by using an ETF wrapper.
• Do not confuse this with full replication in equities (Chapter 18) — the fixed-income chapter's indexing discussion does not use the full-replication-versus-sampling framing by name, even though the underlying idea (mimicking a benchmark) is the same.