U.S. spot Bitcoin ETFs recorded a net outflow of $188.38 million on December 23, continuing a four-day trend of withdrawals. BlackRock's IBIT accounted for the largest share of outflows with $157.08 million, while Fidelity's FBTC, Grayscale's GBTC, and Bitwise's BITB also saw outflows. Other ETFs showed no significant net movement during the same period.