U.S. spot Bitcoin ETFs have experienced a net outflow of $610 million over the past four trading days, according to AiCoin monitoring. The largest outflow was recorded by IBIT, which saw $427 million withdrawn. In contrast, FBTC reported an inflow of $104 million during the same period. These fund flows are noted to have a significant positive correlation with Bitcoin's price movements, as per AiCoin's Spot BTC ETF Tracking strategy.