As central banks unwind quantitative easing (QE), liquidity is increasingly being provided through repo operations instead of continuous asset purchases by the banks. How resilient is this new approach?
Read this article to understand:
- How is liquidity being delivered to financial markets after QE?
- What does the shift to a repo system mean for the markets?
- Why should investors care?
For much of the past decade, investors operated in a world of abundant central bank reserves, where quantitative easing (QE) left excess liquidity sloshing around the system, and questions about funding and market plumbing rarely moved front of mind. That world is changing.
As the Bank of England unwinds QE and reserves decline, liquidity is increasingly being supplied through repo operations rather than permanent balance sheet expansion. The growing use of the bank’s Short Term Repo facility (STR) is one of the clearest signals of this shift (Figure 1).
Figure 1: Bank of England weekly repo STR facility usage, amount outstanding (£ billion)
Note: Bank of England Weekly Report. Weekly amounts outstanding of central bank one-week reverse repos (Short Term Repos - STR) with Bank of England counterparties (in sterling billions), not seasonally adjusted.
Source: Aviva Investors, Bank of England, as of May 27, 2026.
This isn’t a temporary response to stress. It reflects a deliberate move towards a demand driven, collateral based operating framework, where liquidity is accessed when needed – against securities – rather than provided continuously via asset purchases.
Repo has moved from background plumbing to a core component of monetary policy transmission
At the same time, the UK financial system looks very different to how it did a decade ago. Reserves are lower, government bond supply is higher and repo markets are carrying more of the load.
In short, repo has moved from background plumbing to a core component of monetary policy transmission.
That raises a bigger question: if repo markets matter more, are they resilient enough? Recent episodes of market stress offer an important clue.
Market structure matters more now than ever before
During both the 2020 ‘dash for cash’ and the 2022 liability-driven investments (LDI) crisis, the challenge wasn’t a lack of collateral or willingness to transact. It was the system’s limited capacity to intermediate at scale when volatility rose sharply.
Dealer balance sheets became constrained. Repo markets struggled to expand when they were most needed. Liquidity became fragmented and expensive.
Those experiences have sharpened the focus on market structure, particularly in gilt repo. As a result, central clearing has moved from a niche topic to a serious policy discussion.
The logic is straightforward. Centrally cleared repo reduces bilateral counterparty risk, this allows exposures to be netted more efficiently and so can free up dealer balance sheet in periods of stress.
In other words, repo has the potential to increase intermediation capacity exactly when markets are under pressure, rather than when conditions are calm.
This isn’t just a UK debate. In the US, regulators have already committed to expanding central clearing across treasury cash and repo markets. Figure 2 shows the growing volume of short-term repo transactions in the US. The motivation is the same on both sides of the Atlantic: ensuring that core markets remain functional when liquidity demand spikes.
Figure 2: US overnight/open repos volumes ($ billion)
Note: Office of Financial Research, OFR Short-term Funding Monitor – Market Digests. DVP Service, outstanding volumes of overnight/open repos.
Source: Aviva Investors, OFR, as of June 1, 2026.
The critical point is this: as central banks rely more heavily on repo, the resilience of repo markets increasingly shapes the resilience of the financial system itself.
Why should investors care?
At first glance, this can feel like a technical issue best left to central banks, dealers and infrastructure providers. But the implications for investors are real.
First, liquidity becomes more conditional. In a reserve abundant world, markets could absorb shocks almost automatically. In a repo-led system, liquidity depends on collateral, balance sheets and market confidence. When any of those are strained, liquidity can evaporate far faster than investors expect.
In a repo‑led system, liquidity depends on collateral, balance sheets and market confidence
Second, market plumbing affects portfolio outcomes in stress. For liquidity funds and fixed income portfolios, repo market functioning directly influences their access to funding, their counterparty exposure and their transaction costs. Crucially it affects their ability to rebalance during volatile periods.
These differences are largely invisible when markets are calm. They become decisive when volatility rises.
Third, resilience is increasingly about access, not just assets.
Two portfolios holding similar securities can behave very differently if one has more reliable access to funding, more diversified counterparties, or exposure to more resilient market infrastructure.
This is why discussions around central clearing, dealer capacity and collateral velocity are not merely academic. They go to the heart of how risk is transmitted through markets – and whether stress is absorbed or amplified.
Seen this way, the rise of the STR facility and the push to strengthen repo markets are two sides of the same coin. Both reflect a world where liquidity is more precisely targeted, but also more sensitive to how markets are organised.
The bottom line
For investors, the message is simple: when liquidity depends on repo, the resilience of repo markets becomes part of your risk profile
In a QE heavy world, investors could afford to ignore market plumbing. Liquidity was plentiful, blunt and largely taken for granted. In a repo centred world, that luxury disappears.
How liquidity is delivered – through which markets, under what structures, and with what constraints – is becoming a first order investment issue. Not because stress is inevitable, but because when stress arrives, outcomes increasingly depend on whether market infrastructure holds up.
For investors, the message is simple: when liquidity depends on repo, the resilience of repo markets becomes part of your risk profile – whether you intend it to or not.
Understanding that shift won’t just help explain past episodes of volatility. It will help investors better assess how portfolios may behave the next time the system is tested.
