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Level III Core · Portfolio Management for Institutional Investors

Liability-Driven Investing and Asset-Liability Management

Updated 8 October 2026 · Fact-checked

Liability-driven investing (LDI) builds the asset portfolio around the cash flows of known liabilities, so the surplus (assets minus liabilities) stays stable. Asset-liability management (ALM) is the broader process of managing both sides. To solve questions, identify the liability, its risks, the objective and constraints, then choose the approach.

Understand Liability-Driven and Asset-Liability Management Approaches

An institution such as a pension plan, insurer or bank owes money in the future. Those obligations are its liabilities. If you only chase asset returns, the institution can still fail because liabilities move too. The real risk is a fall in the surplus (assets minus liabilities, or the funded status).

Asset-only approaches choose assets using expected return, risk and correlations, with little reference to liabilities. Liability-relative approaches manage the surplus, so liabilities are part of the risk and return picture. Goals-based approaches split money into sub-portfolios, each linked to a goal with its own time horizon and required probability of success. Goals-based is used mostly for individuals, but you should know how it differs.

ALM is the whole process: it looks at both assets and liabilities, their sensitivity to interest rates, inflation and growth, and their liquidity. LDI is a way of carrying out ALM, where assets are chosen to fund or hedge the liabilities. So ALM is the framework and LDI is a specific style within it. Treat them as related, not identical.

Two main LDI tools matter. Cash flow matching buys assets, usually bonds, whose payments line up with each liability date. It removes most interest rate risk but is costly and hard to do exactly. Duration matching (immunization) sets the asset portfolio's present value equal to the liabilities' present value and matches duration, often with convexity of assets at least that of liabilities. It hedges small parallel yield curve shifts but leaves risk for non-parallel shifts and needs rebalancing.

Surplus optimization applies mean-variance thinking to the surplus. The investor maximizes expected surplus return for a given surplus volatility. Liabilities act like a short position in an asset. Many plans split into a hedging portfolio that matches the liabilities and a return-seeking portfolio that targets growth. The mix depends on funded status, sponsor strength and risk tolerance. A weakly funded plan with a weak sponsor should hedge more.

Key rules to remember

Surplus
Surplus = Market value of assets − Present value of liabilities
Funded ratio = Assets ÷ PV of liabilities. A ratio below 1 means a deficit.
Surplus return
Surplus return = (Change in surplus) ÷ (Beginning assets)
Check which base your question uses. Surplus return is often measured relative to beginning assets.
Immunization conditions
PV(assets) = PV(liabilities); Duration(assets) = Duration(liabilities); Convexity(assets) ≥ Convexity(liabilities)
Protects against small parallel yield shifts only. Rebalance as time and yields change.
Duration matching with weights
w1 × D1 + w2 × D2 = D(liabilities), where w1 + w2 = 1
Solve for w1 using w1 = (DL − D2) ÷ (D1 − D2) when two assets are used.
Approximate price change
%ΔPrice ≈ −Modified duration × ΔYield + ½ × Convexity × (ΔYield)²
Use it to compare asset and liability value changes after a yield move.

How to solve Liability-Driven and Asset-Liability Management Approaches questions

Use the same sequence for any LDI or ALM question. It keeps your answer tied to the client and earns the justification points.

  1. 1Read the command word (calculate, identify, justify, recommend) and note how many answers are asked for.
  2. 2Identify the liabilities: size, timing, certainty, and sensitivity to rates, inflation or wages.
  3. 3Find the surplus or funded status, and who bears the risk (sponsor, policyholders, depositors).
  4. 4State the objective and constraints: risk tolerance, liquidity, horizon, regulation and governance.
  5. 5Choose the approach: asset-only, liability-relative or goals-based, then the tool (cash flow matching, duration matching, or a hedging plus return-seeking split).
  6. 6Do the calculation, showing each step and units, such as duration weights or surplus change.
  7. 7Justify in one or two sentences by linking your choice to the client's liability and constraint.
  8. 8Check the answer: does the hedge match both the present value and the duration, and have you answered only what was asked?

Quickest way: Hedge first, then seek return

When to use it: Use when a question asks which approach or allocation suits an institution and you have little time.

  1. Ask: how certain and long are the liabilities? Certain and near means more matching.
  2. Ask: how strong is the sponsor and funded status? Weak means more hedging.
  3. Ask: is there a legal or liquidity limit on risk? If yes, lean to cash flow matching or high-quality bonds.
  4. If the surplus is large and risk capacity is high, allow a bigger return-seeking portfolio.
  5. Write the choice plus one reason tied to the facts.

Common mistakes in Liability-Driven and Asset-Liability Management Approaches

  • Treating ALM and LDI as the same thing.

    Both link assets to liabilities and are often used loosely.

    Fix: Say ALM is the overall process of managing assets and liabilities, and LDI is a liability-focused way to construct the assets.

  • Matching duration but ignoring present value.

    Students remember duration as the key step.

    Fix: Check that asset PV equals liability PV as well as duration. Also check convexity.

  • Claiming immunization removes all interest rate risk.

    The word suggests full protection.

    Fix: State it covers small parallel shifts only, and that non-parallel shifts, credit risk and rebalancing needs remain.

  • Recommending a high-return portfolio for a deficit plan with a weak sponsor.

    Return is the habit from asset-only thinking.

    Fix: Tie risk-taking to ability: weak funding and weak sponsor support point to a larger hedging portfolio.

  • Measuring risk on assets alone in a liability-relative question.

    Volatility of assets is the familiar measure.

    Fix: Use surplus volatility, which includes liability changes and the correlation between assets and liabilities.

  • Giving a long essay answer without a calculation or clear reason.

    Fear of losing points leads to over-writing.

    Fix: Answer exactly what the command word asks, show the number, and add one linked reason.

Worked examples

Example 1

A plan has assets of ₹500 crore and the present value of its liabilities is ₹400 crore. Calculate the surplus and the funded ratio.

Show the solution
  1. Surplus = Assets − PV of liabilities = 500 − 400 = ₹100 crore.
  2. Funded ratio = Assets ÷ PV of liabilities = 500 ÷ 400.
  3. 500 ÷ 400 = 1.25.

Answer: Surplus is ₹100 crore and the funded ratio is 1.25 (125%).

Example 2

A fund must hedge liabilities with a duration of 8 using two bonds: Bond A has duration 4 and Bond B has duration 12. The asset PV equals the liability PV. What weight in Bond A achieves duration matching, and which condition remains to be checked?

Show the solution
  1. Let w be the weight in Bond A. Then 4w + 12(1 − w) = 8.
  2. Expand: 4w + 12 − 12w = 8.
  3. Simplify: 12 − 8w = 8, so 8w = 4.
  4. w = 0.5, so Bond A is 50% and Bond B is 50%.
  5. Check: 0.5 × 4 + 0.5 × 12 = 2 + 6 = 8, which matches.
  6. Remaining condition: asset convexity should be at least liability convexity.

Answer: Hold 50% in Bond A and 50% in Bond B. Then confirm that asset convexity is at least the liability convexity.

Exam tips

  • Read the vignette for funded status and sponsor strength first. Those facts usually decide how much to hedge.
  • In calculations, show the equation and the final number. A correct number alone earns full credit, but working protects you if it is wrong.
  • When asked to justify, link the choice to a liability or constraint in the case, not to general theory.
  • Give exactly the number of answers requested. Only that number is evaluated, in the order given.
  • Know the limits: immunization is for small parallel shifts, and cash flow matching is costly but removes more rate risk.

Liability-Driven and Asset-Liability Management Approaches: frequently asked questions

What is the difference between ALM and LDI?

ALM is the broad process of managing assets and liabilities together, including liquidity and risk limits. LDI is a specific way of building the asset portfolio to fund or hedge liabilities. LDI sits within ALM.

What is the difference between asset-only, liability-relative and goals-based approaches?

Asset-only looks at assets with little reference to liabilities. Liability-relative manages the surplus and includes liabilities in the risk measure. Goals-based divides assets into sub-portfolios for specific goals with set success probabilities.

What is surplus optimization?

It is mean-variance optimization applied to the surplus instead of to assets alone. You seek the highest expected surplus return for a given surplus risk. Liabilities are treated as a short position.

Does immunization guarantee the liability will be met?

No. It protects against small parallel yield shifts when present value, duration and convexity conditions hold. Non-parallel shifts, credit events and lack of rebalancing can still cause a shortfall.