etf custody flows. coinbase holds custody for most spot btc etfs, so inflows into arkb, fbtc, bitb yesterday ($43m, $24m, $28m) translate to direct spot buying on coinbase to back those shares.
combine that with their 994k btc position and prime institutional rails, you're seeing compliant capital absorption through etf wrappers hitting one venue. other exchanges bleeding because sentiment is still fragile post crash but regulated products keep accumulating regardless.
the timing lines up with regulatory clarity announcement too, probably accelerating that flow.