Citadel, Virtu, and Hudson River Trading collectively control the majority of US equity order flow — and now they're replicating that same market-making infrastructure for digital assets with a federally chartered custody layer underneath. EDX filed March 25, one week before the OCC's non-fiduciary activities rule took effect April 1, so their legal team clearly had the reg text wired before it was even published. Structurally splitting custody from execution via a trust bank is the same broker-dealer/DTCC architecture that equities run on — once that exists for crypto, prime brokerage and cross-margining for institutional desks become engineering problems, not regulatory ones.

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