Liability-Driven Investment — the use of interest rate and inflation derivatives or index-linked bond portfolios to hedge the sensitivity of DB scheme liabilities to changes in interest rates and inflation — is standard practice for mature UK Defined Benefit schemes. It addresses the most significant source of funding level volatility: the fact that liability values, as measured on an actuarial basis, change when gilt yields and inflation expectations change. A scheme that does not hedge this sensitivity will see its funding level fluctuate materially with market movements that have nothing to do with the performance of its growth assets or the quality of its investment decisions.
The 2022 UK gilt crisis exposed the contingent risk in these strategies. When gilt yields rose sharply following the September 2022 mini-budget, the derivative positions in leveraged LDI funds required collateral calls. Schemes that had insufficient collateral buffers faced forced sales of growth assets — equities, credit, infrastructure — at the worst possible time, to meet those calls. The losses crystallised were not theoretical. They were real reductions in scheme assets at a point when funding levels were otherwise improving from rising discount rates. The schemes most severely affected saw years of endgame progress reversed in weeks.
Where LDI governance breaks down
The 2022 crisis was not caused by LDI as a strategy. It was caused by inadequate collateral buffers and insufficient stress testing of those buffers against severe interest rate scenarios. These are governance failures, not strategy failures.
Collateral adequacy is a dynamic question. The buffer sufficient to absorb a 100 basis point rate move may be insufficient to absorb a 200 basis point move over a compressed timeframe. Most schemes reviewed their collateral adequacy periodically — typically at investment committee meetings or after significant market moves. Continuous monitoring of collateral headroom against current portfolio leverage, with automatic alerts when headroom falls below defined thresholds, is the governance practice that allows trustees to act before collateral calls are triggered rather than in response to them.
Hedge ratio accuracy represents a second governance dimension. The interest rate and inflation sensitivity of the scheme’s liabilities changes as the membership profile evolves, as pensioners retire and members die, and as the discount rate used for liability calculation changes. A hedge ratio set two years ago against a liability profile that has since changed may be providing less protection than the trustees believe. Regular recalibration of hedge ratios against current liability cash flow projections ensures the protection matches the exposure.
The regulatory response
The Bank of England’s Financial Policy Committee and The Pensions Regulator both issued guidance following the 2022 crisis, expecting DB schemes to maintain LDI collateral buffers adequate to withstand at least a 250 basis point parallel shift in the gilt yield curve. Schemes that cannot demonstrate collateral buffers meeting this standard face regulatory scrutiny and potential enforcement action. The governance response — continuous collateral monitoring, documented stress testing, and trustee reporting that evidences buffer adequacy — is both a regulatory obligation and a genuine risk management improvement.
The technology dimension
Continuous LDI collateral monitoring requires real-time integration of portfolio valuations, liability sensitivity calculations, and rate scenario modelling. For schemes whose investment data and liability calculations are managed through systems running on IBM Z, deploying LDI monitoring models via IBM Machine Learning for z/OS enables continuous collateral headroom assessment against live market data, with alert generation when headroom approaches defined thresholds. The monitoring output is available to trustees and their investment consultant through the governance reporting workflow.
What success looks like
The primary metrics are collateral buffer adequacy against The Pensions Regulator’s 250 basis point standard, hedge ratio accuracy measured against actual liability sensitivity, and the frequency and magnitude of any forced collateral actions. The absence of forced selling in a stress scenario is the ultimate evidence of adequate collateral governance. The pathway to that outcome is continuous monitoring, documented scenario testing, and trustee reporting that keeps the board informed of their collateral position between investment committee meetings — not just at them.
