Millennium Management

Founded by Izzy Englander in 1989, Millennium Management is one of the pioneers and largest players in the multi-manager, or 'pod,' model: capital is split across many independent trading teams, each running its own strategy under strict risk limits, rather than one central investment view driving the whole firm. That structure is designed to diversify away any single team's blowup risk, though it also means overall performance depends heavily on how well the firm manages dozens of pods simultaneously.