The 2022 UK Gilt Crisis: How a Pension Hedge Became a Financial Stability Threat

On September 23, 2022, the UK government announced a package of large, largely unfunded tax cuts. Within days, long-dated UK government bond yields were moving by more in a single session than they typically moved in months, and the Bank of England found itself buying gilts to prevent what it later described as a risk to the country's financial stability. The mechanism connecting a tax announcement to a central bank intervention runs through a corner of the pension industry most people had never heard of before that week.

September 23: the announcement. The UK's new government unveiled its "Growth Plan," a set of tax cuts unfunded by corresponding spending cuts or clearly identified financing, at a scale that surprised investors both in size and in the absence of an accompanying independent fiscal forecast. Gilt yields, already rising with global rates through 2022, began moving sharply higher as investors priced in a larger issuance need and a higher risk premium on UK fiscal policy.

The move that followed was historically large. Between September 22 and September 28, the 30-year gilt yield rose by around 130 basis points, a move the Bank of England later described as roughly three times larger than any other similar move it could identify in recent history. That kind of move in long-dated government bonds, an asset class usually considered a stable, low-volatility holding, is what turned this into more than an ordinary bad week for bond investors.

The mechanism: liability-driven investment. UK defined-benefit pension schemes commonly use a strategy called liability-driven investment, or LDI, which uses leveraged gilt holdings and derivatives to hedge the schemes' long-dated liabilities against interest-rate moves. That leverage works in both directions. When gilt yields spiked, the value of the leveraged positions moved against the funds holding them, triggering margin calls, demands for additional collateral to keep the hedges in place. To meet those calls, funds sold gilts, which pushed gilt yields higher still, which triggered further margin calls elsewhere in the system. It was a feedback loop where the standard response to the stress, sell gilts to raise cash, made the underlying stress worse.

September 28: the Bank of England intervenes. Citing a risk to UK financial stability, the Bank of England announced it would temporarily and specifically purchase long-dated conventional gilts, with a pre-announced end date of October 14, a deliberately time-limited operation aimed at breaking the feedback loop rather than a general, open-ended commitment. On October 10, with stress persisting, the Bank raised the maximum daily purchase size from £5 billion to £10 billion for the final week, and on October 11 it expanded the operation to include index-linked gilts as well.

October 14: the intervention ends, on schedule. The Bank's gilt purchases ended on the date it had originally set, having bought a total of £19.3 billion in gilts, £12.1 billion conventional and £7.2 billion index-linked, over 13 working days. The Bank began unwinding those purchases on November 29, 2022, completing the sale over 12 trading days by January 12, 2023.

Why the Bank couldn't just watch. The size of the initial yield move mattered, but the mechanism mattered more: leverage inside a part of the pension system that most gilt investors weren't tracking closely turned an already large fiscal repricing into a self-reinforcing market-functioning problem, one with the potential to impair the gilt market itself, the market the UK government depends on to finance its debt. The Bank wasn't trying to hold yields at any particular level. It was providing a credible, temporary backstop that broke the fire-sale dynamic and bought LDI funds time to raise liquidity and reduce their leverage, which is also why it could pre-announce an end date rather than leaving the operation open-ended.

Leverage tends to be invisible in calm markets and highly visible in stressed ones, and it can convert an ordinary repricing into a self-reinforcing spiral regardless of which asset class or which type of institution is holding it. The specific instrument here was LDI, but the pattern, a price move triggering margin calls, margin calls forcing sales, sales deepening the price move, shows up whenever leveraged positions are large relative to the market's normal capacity to absorb selling.