# The Federal Reserve and the Bank of England step up scrutiny of bank lending to trading firms after Jane Street's loss

Regulators are questioning prime brokers about their exposure after the collapse of an artificial-intelligence-focused hedge fund forced a distressed sale of its holdings.

- Published: 2026-09-21T05:16:54.216Z
- Canonical: https://polylog.news/2026-09-21/the-federal-reserve-and-the-bank-of-england-step-up-scrutiny
- Publisher: Polylog (Global desk)
- Section: markets
- Sources: [Financial Times](https://www.ft.com/content/f1d9d398-0666-44cf-96f4-390e6c3f5173?syn-25a6b1a6=1), [Financial Times](https://www.ft.com/content/01a7b883-452c-4902-b40e-e3957de5d89e?syn-25a6b1a6=1)

The Federal Reserve and the Bank of England have intensified their questioning of prime brokers about the risks banks carry through their financing relationships with large trading firms, [following the loss at Jane Street tied to the collapse of the hedge fund Situational Awareness](https://www.ft.com/content/f1d9d398-0666-44cf-96f4-390e6c3f5173?syn-25a6b1a6=1). The Federal Reserve is running a parallel review of how American banks manage counterparty exposure to major trading houses.

Situational Awareness, run by the former OpenAI researcher Leopold Aschenbrenner, [lost roughly 35 billion dollars in assets after margin calls from its prime brokers forced a distressed sale](https://finance.yahoo.com/markets/stocks/articles/jane-street-15-billion-loss-131134588.html) of its listed holdings to Citadel. The prime brokers were Bank of America, Goldman Sachs and JPMorgan, and leverage was reported at about four times capital. Jane Street lost approximately 15 billion dollars in July, and said the hedges it held gave little protection because the losses in artificial-intelligence shares accumulated over weeks rather than arriving all at once.

Valuations in the same sector keep rising. The Financial Times' Lex column argues that [a two trillion dollar valuation for Anthropic is plausible](https://www.ft.com/content/01a7b883-452c-4902-b40e-e3957de5d89e?syn-25a6b1a6=1) and that several valuation methods suggest an even higher figure.

Both facts belong to one process. Cheap and abundant financing lets concentrated bets on a single theme scale up through bank balance sheets, and the losses surface only when the collateral is marked. Regulators are now examining the financing channels that carried the bet, the standard sequence once credit expansion meets a crowded position.

## What this means

The exposure sits with the prime brokerage units of large banks, which earn fee income from financing concentrated funds and discover the risk only when a forced sale prices the collateral. Tighter margin requirements or lower leverage limits would reduce the buying power behind artificial-intelligence equities, which is the channel through which a supervisory review reaches share prices. Investors in bank shares face a fee-income question, and holders of the most crowded technology names face a positioning question, because the same financing that amplified the rally amplifies the exit.

## What to watch

- Whether the Federal Reserve or the Bank of England publishes formal guidance on counterparty limits, which would apply to every prime broker rather than to the firms being questioned now.
- Reported prime brokerage revenue at Goldman Sachs, JPMorgan and Bank of America in the next results, the first visible sign of whether banks are pulling back financing.
- Private-market funding rounds for large artificial-intelligence developers, since a slowdown there would test valuation assumptions that public holdings rest on.