The system-wide exploratory scenario (SWES) is voluntary, but its implications are not. With UK private credit assets roughly tripling since 2018, according to Bank of England and FCA assessments, and private capital now embedded in the funding and exit strategies of thousands of mid-market businesses, the exercise marks a clear shift: private markets are moving from a lightly supervised fringe into what regulators treat as a core part of the UK financial system.

What the stress test actually assumes

The SWES scenario, published by the Bank of England on 19 June 2026, models a five-year downturn triggered by a hypothetical fracturing of global trade. Its key parameters are stark:

  • UK base rate rises to 7%, well above the 5.75% peak reached in 2007.
  • Inflation hits 7%, surpassing the roughly 5.2% CPI peak recorded during the 2008 crisis.
  • Equities fall 35%, a historic bear market.
  • AI-driven disruption accelerates, hammering software-as-a-service (SaaS) valuations, while a simultaneous slowdown in AI investment, driven by higher energy prices, weighs on another popular private equity sector.

Participants include alternative asset managers such as Ares, Carlyle, Blackstone, KKR and Oaktree, alongside traditional banks including Goldman Sachs and Barclays. Each must log how it would respond to the scenario. The Bank of England plans to publish results later in 2026, followed by a second round of questioning where officials probe any answers they do not consider realistic, as reported by City AM.

Michael Moore, chief executive of UK Private Capital, the industry body, described the scenario as "very severe" and called for comparable treatment across the financial system.

"It matters that everyone can see how all parts of the financial system would react in the same circumstances, and how that would impact on the real economy on a comparable basis."

Jiri Krol, deputy chief executive of the Alternative Investment Management Association, called the exercise "deliberately very severe" but welcomed it as "evidence-based", adding that it should help counter what he described as "generalised, anxiety-inducing speculation" about the sector's opacity.

Why private capital matters to mid-market operators

For many UK scale-ups and mid-market companies, private capital is no longer a niche funding source. It is the primary alternative to bank lending for growth finance, acquisition funding and refinancing. Private credit funds have filled gaps left by banks retreating from riskier lending after the post-2008 regulatory tightening. Private equity-backed acquirers, meanwhile, represent a significant share of the buyer pool for founder exits and secondary buyouts.

The stress test matters to these businesses for two practical reasons.

First, if the exercise exposes fragility in how private credit funds manage liquidity or mark assets, regulators could tighten lending standards, slow deployment or impose new disclosure requirements. That would directly affect the availability and cost of capital for borrowers. Covenants could become more restrictive. Refinancing timelines could lengthen.

Second, the scenario's assumptions about asset-price declines and interest-rate shocks provide a window into how fund managers might behave in a real downturn. Operators negotiating terms with private lenders or considering PE-backed exits should understand that the Bank of England is, in effect, asking their capital providers to demonstrate whether they can absorb severe losses without fire-selling assets or withdrawing credit lines.

The collapse of Mayfair-based direct lender Market Financial Solutions in 2025, which is now subject to an FCA investigation as reported by City AM, intensified regulatory concern about underwriting standards in the sector. That episode underscored the risk that rapid growth in private credit had, in some corners, outpaced risk management.

The SaaS and AI wrinkle: sector-specific risks under the microscope

The SWES scenario devotes considerable attention to technology. This is not incidental. Private equity and direct lending funds have poured capital into SaaS businesses over the past decade, attracted by recurring revenue models and high margins. More recently, AI-related investments have become a significant allocation for many funds.

The Bank of England's scenario tests both sides of that trade simultaneously. SaaS companies "judged as having weaker competitive advantages or a 'smaller moat'" will, under the scenario, shed a disproportionately large share of their valuation, according to the SWES documentation. At the same time, the scenario models a slowdown in AI adoption driven by higher energy prices weighing on demand for compute.

For mid-market software businesses, this is directly relevant. Many have been valued on revenue multiples that assume continued growth and defensible market positions. If stress-test results suggest that fund managers would aggressively mark down such holdings under duress, it could recalibrate how PE firms price acquisitions and how lenders underwrite loans secured against software businesses.

The dual shock is also a test of portfolio concentration. Funds that are heavily exposed to both SaaS and AI infrastructure face correlated losses under the scenario. If the Bank of England concludes that concentration risk is poorly managed, it could prompt guidance that encourages diversification, potentially redirecting capital flows away from technology and towards other sectors.

What happens next, and what operators should watch for

The immediate timeline is clear. Participants submit their responses, the Bank of England analyses them, and results are published later in 2026. A second round of follow-up questioning will probe areas where the regulator is not satisfied with the realism of firms' answers.

The longer-term consequences are less certain but worth tracking.

Regulatory follow-through. The SWES is described as "exploratory", meaning it is designed to build understanding rather than to impose pass-or-fail capital requirements. But exploratory exercises have a habit of producing findings that inform future policy. If the Bank of England identifies systemic vulnerabilities, it could recommend new rules for private fund managers operating in the UK, or feed findings into the FCA's ongoing work on private market transparency.

Lending terms. Even before formal regulatory action, the exercise itself may change behaviour. Fund managers who discover weaknesses in their own stress-testing may tighten underwriting standards pre-emptively. Borrowers could see higher pricing, tighter covenants or shorter commitment periods.

Valuation discipline. The scenario's assumptions about SaaS write-downs and AI slowdowns may prompt funds to revisit how they mark portfolio companies. Greater valuation conservatism would affect reported fund performance and, by extension, the multiples at which PE firms are willing to transact.

Cross-sector comparability. Moore's call for comparable treatment across the financial system is significant. If private markets are stress-tested more severely than banks or insurers, the industry will argue that the playing field is uneven. If the tests are eventually harmonised, the result could be a more integrated regulatory framework for all capital providers, with implications for how businesses choose between bank and non-bank funding.

The Bank of England's first foray into stress-testing private markets is, at its core, an acknowledgement that these markets are now too large and too interconnected to remain outside the regulatory perimeter. For the mid-market businesses that depend on private capital, the practical question is not whether regulation is coming, but how quickly it will reshape the terms on which that capital is available.