arkets"-". More specifically, Brock and colleaguesw have shown that proliferation of hedging instruments can destabilize markets. Building on this, Caccioli and colleague?' note that APT makes several conventional assumptions upon which everything else depends: "perfect competition, market liquidity, no

sness, resulting in a focus on creating institutional arrangements that seek to guarantee the premises upon which APT is bestir". To the contrary, Caccioli and colleagues argued" that APT is not a 'theory' in the sense habitually used in the sciences, but rather a set of idealized assumptions on which