The Bank of England has stepped up scrutiny of global banks over their exposure to major trading firms after Jane Street suffered a roughly $15 billion hit during July’s sharp market turmoil.
The Bank of England and the US Federal Reserve are now examining how banks manage their relationships with large trading firms. Their focus includes intraday exposure, risk limits and whether banks had strong enough controls when markets came under pressure.
The move brings fresh attention to the growing links between major banks and non-bank trading firms.
What Triggered the Bank of England Scrutiny?
The regulatory focus follows heavy losses linked to a sell-off in artificial intelligence and semiconductor stocks.
Situational Awareness, an AI-focused hedge fund run by former OpenAI researcher Leopold Aschenbrenner, was caught in the market decline. Margin calls forced the fund to sell much of its public equity portfolio to Citadel Securities.
Jane Street had investments linked to the fund as well as other technology positions. The market shock contributed to an estimated $15 billion loss for the trading firm in July. The event has raised a wider question for regulators: how much risk can build up between banks and large trading firms before traditional reporting systems reveal the full exposure?
Why Is Intraday Risk Under the Spotlight?
The key concern is what happens during the trading day. A bank may appear to have a manageable exposure at the end of the day. However, its position can change sharply within hours as clients trade, borrow, post collateral or face margin calls.
That matters because large principal trading firms rely on banks for leverage, clearing, payments and market access.
The Prudential Regulation Authority had already warned about this risk before the July market shock.
In February 2026, the PRA said principal trading firms had become important liquidity providers across financial markets. Some now generate trading revenues comparable with major investment banks. At the same time, these firms remain closely connected to banks through financing and other services. The latest inquiry will now examine whether banks are properly tracking those risks while markets are still moving, rather than relying mainly on end-of-day positions.
Who Does This Matter To?
The immediate scrutiny applies to major banks and their relationships with large non-bank trading firms. However, the issue also matters to finance leaders because it highlights the risks created by leverage, concentrated exposure and limited visibility.
For businesses, the lesson is not that ordinary companies face the same risks as Jane Street. Instead, it shows how quickly financial pressure can build when several risks are connected.
Heavy dependence on one market, counterparty or source of funding can become more serious when conditions suddenly change, a risk that is just as relevant to small and medium-sized businesses leaning on a single lender or key customer.
What Should Finance Leaders Do Now?
UK businesses do not need to react to the investigation as if new banking rules have already been introduced. No new requirement has yet been announced as a direct result of the inquiry. However, finance teams can use the case as a reminder to review their own risk controls.
Businesses should understand their debt exposure, monitor available liquidity and identify areas where too much reliance sits with one customer, supplier, lender or investment, ideally with support from a virtual finance director who can keep this under regular review.
Cash-flow forecasts and stress testing can also help management see how the business may respond if financing conditions or expected payments change suddenly. Our guide to cash flow forecasting for UK SMEs covers the basics of building this into your planning.
Why Trust Lanop?
Lanop helps businesses look beyond year-end figures and understand the financial risks that can affect day-to-day decisions.
Our team supports UK businesses with cash-flow forecasting, financial planning, management reporting and strategic advisory services as part of wider tax planning. As regulators place greater attention on liquidity, leverage and financial resilience, having clear and timely financial information can help business leaders make better-informed decisions before pressure builds. Contact Lanop today to review your business’s financial resilience and risk exposure.
