The Bank of England’s deputy governor Sarah Breeden on Tuesday said Agentic AI’s cyber capabilities were her most immediate financial stability concern.

Speaking at the European Central Bank Forum on central banking in Portugal, Breeden said AI agents - which can act autonomously — could amplify volatility in times of stress, raising questions over whether the financial system can observe and contain their behaviour.

"We must keep asking whether existing, technology-agnostic regulatory frameworks remain sufficient. Our frameworks were not built to contemplate autonomous agents, and relying on a human in the loop for all agent actions is unlikely to be realistic. More sophisticated governance and accountability frameworks may be needed," she said.