“…Similar to the James-Stein estimator [Stein, 1955], the MRE framework provides a sound rationale for shrinkage estimates, which blend a pure statistical estimate, such as the historical variance, in order to satisfy additional constraints implied by the market views, such as target bounds on volatilities. MRE approach have already been extensively used in …nance for applications including derivatives pricing ([Avellaneda, 1999], [D'Amico et al, 2003]), portfolio allocation ( [Pezier, 2007]), stress-testing ( [Breuer and Csiszar, 2013]), and, more broadly, in risk and portfolio management [Meucci, 2008], [Meucci, 2013], , [Meucci, 2012b], [Meucci and Nicolosi, 2016].…”