The Basel Committee on Banking Supervision’s (“BCBS’s”) second full consultative document on the fundamental review of the trading book (“FRTB”) , supplemented by a third paper in December 2014 covering outstanding issues , sets out significant revisions to the market risk capital requirements framework. Key areas include moving from Value at Risk (“VaR”) to Expected Shortfall (“ES”), varying liquidity horizons, the trading book/banking book boundary, the treatment of credit, hedging and diversification, and the relationship between the internal models-based and standardised approaches. The FRTB document succeeded the Committee’s initial consultation from the previous year. Its proposed revisions are part of a broader reform agenda in response to the material weaknesses exposed in the financial crisis, and they incorporate the lessons learned from recent investigations into the variability of market Risk-Weighted Assets (“RWA”). This note reviews the FRTB changes to internal models-based market risk approaches – Expected Shortfall, confidence level, liquidity horizons, stressed ES, migration risk and backtesting -- assessing their implications for firms and capital requirements.