In the aftermath of the financial crisis, the FSB and the G20 identified more intense and effective supervision of SIFIs, particularly G-SIFIs, as critical to the safety and stability of the financial system. Since the crisis, the FSB has explored the changes in tools and methods used by supervisors in order to intensify supervision, and set out recommendations aimed at improving supervisory effectiveness. The review assesses progress towards implementing these recommendations for SIBs since the financial crisis, in particular for G-SIBs. It takes stock of key changes that have been made in supervisory frameworks and approaches for SIBs, and highlights where new practices and tools have led, or could lead, to more effective supervision. The review finds that supervision has become more risk-based; supervisory tools such as business model analysis, stress testing and horizontal reviews have been enhanced and are increasingly used to provide a more forward-looking approach, capturing both current and emerging risks. The scope of supervision has also expanded to incorporate macroprudential and resolvability considerations, and the dialogue with institutions has been enhanced. These findings are also reflected in the feedback from 13 G-SIBs that were surveyed as part of the peer review. The G-SIBs noted an increase in supervisory intensity, in particular on capital and liquidity, and many highlighted an increase in the number and depth of supervisory reviews and data requests. The report sets out several recommendations to further improve and assess supervisory effectiveness and to foster greater cross-border supervisory cooperation and coordination.