What Is the Regulatory Stance on the Use of ‘Last Look’ in Major Financial Markets?

Regulatory bodies, particularly in FX and some derivatives markets, have expressed significant concerns about 'last look' due to its potential for adverse selection and unfair trading practices. While not universally banned, regulators like the UK's FCA have issued guidance emphasizing that 'last look' must be used fairly and transparently.

Misuse, such as rejecting orders based on latency arbitrage, is often considered market abuse and is subject to enforcement actions.