This paper considers the banking system from the respective points of view of EU monetary and competition policy, and the issues that arise when excess credit creates an asset price bubble and crash. Banks are subject to competitive pressures, but are interdependent to a higher degree than most firms. Potential competition policy responses to this combination of features could include monitoring by the monetary and competition authorities to see if a concerted practice is involved where there is excessive bank lending; making co-ordinated behaviour between competing banks subject to the normal competition law requirement that it should provide economic benefits in the real economy, and to consumers; and, if it is established that an asset price bubble and crash has resulted from a concerted practice, adjusting the overhang of debt down to the pre-bubble value of the asset.