The Options Clearing Corporation ("OCC") appreciates the opportunity to provide comments on the BCBS-CPMI-IOSCO (collectively, the Joint Working Group on Margin, or “JWGM”) Consultative report, Transparency and responsiveness of initial margin in centrally cleared markets – review and policy proposals (the “Report”). As a systemically important central counterparty (“CCP”) and the sole US CCP for listed equity options, OCC is pleased to participate in the ongoing dialogue between CCPs, clearing members, end users, and international standard setting bodies on optimizing margin transparency in cleared markets.