This article analyses regulatory arbitrage in financial markets from a risk-based perspective. It assesses regulatory arbitrage in terms of the risk it may pose to the attainment of a regulatory objective, in this case financial stability. Its most distinct contribution to the literature is the application of the NOAEL approach—thus far mainly used in public health literature and regulatory toxicology—to the legal analysis and management of arbitrage risks. We propose several qualitative parameters relating to the likelihood of regulatory arbitrage and the negative impact if such arbitrage should occur. The article ultimately aims to help frame the ongoing debate about policy-making and the use of risk assessment methodologies to cope with regulatory arbitrage in financial markets.