Liability-driven investment, usually shortened to LDI in finance, is a pension portfolio strategy that measures success not by how much the assets earned but by how closely they track what the plan owes. Instead of aiming for the highest possible return, an LDI program is built around the plan’s benefit obligations, using long-duration bonds and derivatives to hedge changes in those liabilities while a smaller growth sleeve works to close any remaining funding gap. It became the default approach for corporate defined benefit plans because it directly addresses the risk that keeps sponsors up at night: a sudden widening of the gap between what the plan holds and what it has promised to pay.
The Two Sleeves
Every defined benefit plan carries a set of promises: monthly checks to retirees, survivor benefits, and future payouts to workers still on the job. The present value of those promises is the plan’s liability, and under U.S. accounting rules the discount rate applied to it comes from yields on high-quality corporate bonds. That means the liability’s dollar value moves every day as bond markets move.
The funding ratio is plan assets divided by that liability. A plan at 100% is fully funded; below that, the sponsor eventually has to close the deficit with cash. LDI exists to keep that ratio stable, because without a hedge a sponsor can find itself writing an enormous check to the pension trust after a year in which falling interest rates inflated the liability by billions even though the stock portfolio performed fine.
To do that, the LDI manager splits the portfolio into two sleeves:
- A hedging portfolio of long-duration bonds and derivatives designed to rise and fall alongside the liability.
- A growth portfolio of equities, real estate, or other return-seeking assets aimed at closing any remaining funding gap.
The ratio between the two shifts over time as the plan’s funded status improves. That shift is where most of the discipline lives, and it’s covered further down.
How Duration Matching Works
Duration is the concept that makes the hedge possible. It measures how sensitive a bond’s price is to a change in interest rates, expressed as a weighted average of the time until cash flows arrive. A bond with a duration of 15 years will lose roughly 15% of its value if rates rise by one percentage point and gain roughly 15% if rates fall by the same amount. Pension liabilities have duration too, because they are essentially a stream of future cash flows discounted at current interest rates.
The manager’s first job is to match the duration of the hedging assets to the duration of the liabilities. If the liability has a 15-year duration, the hedging portfolio needs to show the same sensitivity. When rates fall, the liability grows more expensive, but the hedging assets gain by a comparable amount. When rates rise, both sides shrink together. The funding ratio stays roughly flat either way, which is the whole point.
Perfect matching is more theory than reality. Interest rates don’t move uniformly across all maturities; the yield curve can steepen, flatten, or twist in ways that affect 5-year and 30-year bonds differently. Pension liabilities also contain embedded features like early retirement subsidies and lump-sum options that make their behavior harder to predict. Duration matching provides a strong first-order hedge, not a set-and-forget solution.
Calculating a liability’s duration is genuinely complex. Active employees haven’t yet determined when they’ll retire or what their final salaries will be, and some projected payments stretch well beyond 30 years into the future. Plans with younger workforces carry longer liability durations, sometimes exceeding 20 years, which makes the hedging task steeper.
Cash Flow Matching for Near-Term Payments
Duration matching handles broad interest rate exposure, but plans that are closed to new participants or heavily tilted toward retirees face a different problem: they need actual cash flowing out the door every month. For these plans, cash flow matching supplements or replaces duration matching for near-term obligations.
Cash flow matching means buying bonds whose coupon and principal payments land in the same months that benefit checks are due. A retiree population collecting $20 million per month needs a bond ladder producing roughly $20 million per month in predictable income. Reinvestment risk on those near-term payments disappears entirely because there’s nothing to reinvest. The cash arrives and goes straight to retirees.
The tradeoff is flexibility. Duration matching lets the manager use any combination of instruments to hit a target sensitivity number; cash flow matching locks specific bonds to specific dates. Most mature LDI programs use both: cash flow matching for the next 10 to 15 years of retiree payments, duration matching for the longer-tail obligations that are harder to match precisely with available bonds.
What Goes Into the Hedging Portfolio
Long-dated bonds form the foundation. Treasury bonds with 20- or 30-year maturities provide credit-risk-free duration. Investment-grade corporate bonds offer higher yields and a closer match to the discount rate used to value the liabilities. Treasury STRIPS, which separate a bond’s principal and interest payments into individual zero-coupon securities, deliver the longest duration per dollar because there are no interim coupon payments pulling the duration shorter.1TreasuryDirect. Separate Trading of Registered Interest and Principal of Securities
Physical bonds alone rarely provide enough duration. A plan with $1 billion in assets and a 15-year liability duration would need to invest the entire portfolio in very long bonds just to match, leaving nothing for growth assets. Derivatives solve this by creating synthetic duration exposure at a fraction of the capital cost.2European Central Bank. Measuring Synthetic Leverage in Interest Rate Swaps The common instruments include:
- Interest rate swaps, where the plan pays a floating rate and receives a fixed rate, synthesizing a long bond position without buying the bond.
- Treasury futures, standardized contracts on long-dated Treasuries that provide rate exposure with daily margin settlement.
- Total return swaps, where the plan receives the total return of a bond index in exchange for a financing rate, gaining exposure to an entire portfolio through a single contract.
- Repurchase agreements, where the plan pledges high-quality government bonds as collateral and borrows cash, which it reinvests in additional bonds or derivatives.
Plans with inflation-sensitive obligations, like cost-of-living adjustments tied to the Consumer Price Index, can hedge that exposure separately using inflation swaps. The plan pays a fixed rate and receives a payment linked to realized inflation, directly offsetting the risk that rising prices will increase the benefits owed.
Leverage and Collateral Risk
Using derivatives to create synthetic duration is, by definition, using leverage. Consider a plan with £100 of liabilities at a 20-year duration. Investing the full £100 in 20-year bonds would match the exposure without leverage. But if the plan wants to free up half its assets for growth investments, it can invest just £50 in bonds with a 40-year duration and achieve the same interest rate exposure with half the capital. That’s 2x leverage. Pushing further to 3x or 4x frees up more for equities but sharply amplifies vulnerability to sudden rate moves.
When rates spike, the value of the hedging assets drops and the derivatives counterparties demand additional collateral, known as margin calls. At 2x leverage, a 50-basis-point yield shock is uncomfortable but manageable. At 4x, the same shock can push the effective leverage ratio up by 50%. At 5x, a 100-basis-point move can theoretically wipe out the hedging portfolio’s equity entirely. The relationship between leverage and fragility is not linear.
Managing this collateral flow is one of the most operationally intensive parts of running an LDI program. The manager maintains a collateral waterfall: a predetermined list of which assets get sold first when cash is needed. Typically the most liquid holdings like equity funds get tapped first, followed by less liquid alternatives if the initial buffer isn’t enough. Setting that priority in advance keeps crisis decisions mechanical rather than emotional.
The LDI manager tracks the mark-to-market value of all derivative positions daily and forecasts how much collateral might be needed under various rate scenarios. The goal is to always have enough liquid assets on hand to meet margin calls without being forced to sell long-duration bonds at distressed prices, because selling those bonds would reduce the hedge ratio at exactly the wrong moment.
The 2022 UK Gilt Crisis
The risks of leveraged LDI stopped being theoretical in September 2022. After the UK government announced an unexpected fiscal stimulus package, 30-year gilt yields jumped 140 basis points in three days.3International Monetary Fund. Liability-Driven Investment Crisis: United Kingdom UK pension funds running leveraged LDI programs faced massive margin calls practically overnight.
The mechanics were brutal. Rising yields reduced the net asset value of LDI funds, triggering demands for additional collateral. Many pooled LDI funds couldn’t raise cash fast enough from their pension fund investors, so they were forced to sell gilts to deleverage. That selling pushed yields even higher, which triggered more margin calls on other funds, creating a self-reinforcing spiral. UK pension schemes and LDI funds faced an estimated £70 billion in margin and collateral calls and sold roughly £37 billion in gilts.3International Monetary Fund. Liability-Driven Investment Crisis: United Kingdom The Bank of England intervened, purchasing £19.3 billion in gilts before ending its emergency program in October and unwinding those purchases by January 2023.4Federal Reserve Bank of Chicago. UK Pension Market Stress in 2022
The irony sits at the center of the episode. Rising rates actually improved pension funded ratios, because liabilities shrank faster than assets. The problem wasn’t solvency. It was liquidity. Plans were healthier on paper but couldn’t meet the cash calls on their derivative positions fast enough. Any sponsor evaluating an LDI program should stress-test its collateral buffers against rate shocks of 150 basis points or more.
The De-Risking Glide Path
Most LDI programs don’t launch at full hedge. Instead, the investment committee adopts a glide path: a set of predetermined rules that shift the asset allocation from growth assets toward hedging assets as the funding ratio improves. The logic is intuitive. An underfunded plan needs growth to close the gap; a fully funded plan has no gap to close and should lock in its position.
A typical glide path might allocate 35% to liability-hedging bonds when the plan is 80% funded, stepping up to 55% at 90%, 75% near full funding, and 90% or more once the plan is comfortably overfunded. The triggers are automatic. When the funded ratio crosses a threshold, the rebalancing happens without a committee vote, which removes the temptation to keep chasing returns after the plan has already won.
Without a glide path, plan sponsors tend to behave like individual investors: hold risky assets when things feel good, panic into safe assets after a drawdown. The glide path reverses that impulse by systematically locking in gains. A plan that reaches 105% funded and immediately shifts 90% into hedging has protected itself against the scenario where equity markets give back the surplus.
One practical nuance: triggers should be based on the plan’s own actuarial liability, not a generic market-based measure. A plan with young employees and a long-duration liability behaves differently from a frozen plan paying retirees, and off-the-shelf target-date glide paths from pooled fund providers are a compromise at best.
Why Sponsors Bother
LDI is partly a response to federal law. Under ERISA, single-employer plans must make minimum required contributions each year, and when plan assets fall below the funding target the sponsor owes the normal cost of benefits accruing that year plus a shortfall amortization charge spread over seven years.5Office of the Law Revision Counsel. 29 USC 1083 – Minimum Funding Standards for Single-Employer Plans Underfunded plans also owe a variable-rate premium to the Pension Benefit Guaranty Corporation. For 2026, that premium is $52 for every $1,000 of unfunded vested benefits, capped at $751 per participant.6Pension Benefit Guaranty Corporation. Premium Rates A plan with $500 million in unfunded benefits faces a PBGC bill of $26 million before a single benefit check goes out. Getting and staying fully funded eliminates that variable premium entirely.
ERISA also holds plan fiduciaries personally liable if they fail to act prudently, requiring the care, skill, and diligence of a prudent person familiar with such matters.7Office of the Law Revision Counsel. 29 USC 1104 – Fiduciary Duties Fiduciaries must diversify investments to minimize the risk of large losses and must run the plan solely in the interest of participants.8U.S. Department of Labor. Fiduciary Responsibilities An investment committee that ignores liability risk in favor of aggressive return-chasing is exposed personally if the bet goes wrong.
Good governance for an LDI program means the committee has documented policies for at least three things: the conditions that trigger a glide path shift, the acceptable range of leverage and collateral buffers, and the process for evaluating and replacing managers. These policies should be written before a crisis, not improvised during one.
Counterparty risk deserves ongoing attention because derivative positions create direct credit exposure to the institution on the other side. For standardized interest rate swaps, central clearinghouses reduce this risk by standing between the two parties and guaranteeing settlement.9Bank for International Settlements. Central Clearing Predominates in OTC Interest Rate Derivatives Markets The Dodd-Frank Act requires certain standardized swaps to be centrally cleared for this reason.10Office of the Comptroller of the Currency. Commodity Futures Trading Commission Swap Clearing Rules For customized over-the-counter swaps that don’t go through a clearinghouse, the plan should diversify across multiple high-credit-quality counterparties and maintain robust collateral agreements.
What LDI Doesn’t Cover
LDI handles interest rate risk and inflation risk well, but it does little for longevity risk, the possibility that retirees live longer than the mortality tables predicted. If participants outlive their assumed life expectancies, the plan pays benefits for additional years that were never factored into the liability calculation, and no amount of duration matching fixes that.
Mortality improvements are inherently uncertain. Actuaries build current mortality experience into their projections, but those projections are backward-looking. A medical breakthrough or shift in lifestyle patterns can change the trajectory in ways historical data doesn’t capture. ERISA requires plans to use reasonable mortality assumptions based on plan experience, so the exposure is acknowledged but not eliminated. Some sponsors address longevity risk outside the investment portfolio entirely, through pension risk transfers or by purchasing longevity insurance from reinsurers.
The Endgame
For many corporate sponsors, LDI isn’t the destination. It’s the road to the exit. The ultimate goal of a de-risking glide path is often a pension risk transfer: paying an insurance company to take over some or all of the plan’s benefit obligations through a group annuity contract.
The connection is practical. Insurance companies price buyout annuities based on the yields available on investment-grade corporate bonds and Treasuries. A well-designed LDI portfolio already holds those instruments. When the plan reaches full funding and the glide path has shifted nearly everything into hedging assets, the portfolio closely resembles what the insurer needs, and some insurers offer better pricing when the plan can transfer bonds in-kind rather than liquidating and wiring cash.
Plans that aren’t ready for a full buyout sometimes adopt a hibernation strategy: maintaining a fully hedged LDI portfolio indefinitely, paying benefits from bond cash flows, and accepting minimal funded-status volatility while waiting for the right moment to transact. This works well when annuity pricing is unattractive or when the plan is too large to transfer in a single deal.
As of late 2025, aggregate U.S. corporate pension funded ratios sat above 100%, driven largely by higher interest rates shrinking liability values. That overfunded position has accelerated the pace of pension risk transfers, as sponsors recognize the window of favorable pricing won’t stay open forever. For these plans, LDI did exactly what it was designed to do: capture the improvement in funded status, lock it in through the glide path, and position the portfolio for a clean handoff to an insurer.