U.S. spot Bitcoin exchange-traded funds closed the week in positive territory after Friday’s single-day net inflow of $433 million rescued what had been a sluggish period. Fidelity’s FBTC led the Sept. 18 session with $310.72 million, while BlackRock’s IBIT attracted $108.44 million. Smaller contributions came from Bitwise’s BITB with $9.7 million, VanEck’s HODL with $2.3 million, and ARK Invest’s ARKB with $1.9 million. No listed fund recorded an outflow during the session.
The late-week rebound followed heavy withdrawals earlier in the week. Spot funds lost $450.4 million on Sept. 15 and $295.9 million on Sept. 16, a combined $746.3 million. Flows recovered by $592.5 million across Sept. 17 and Sept. 18, leaving part of the earlier deficit unrecovered. Cumulative net inflows reached $55.23 billion through Sept. 18, while BlackRock’s official product page listed IBIT net assets near $59.87 billion. Both Fidelity’s FBTC and BlackRock’s IBIT charge a stated fee of 0.25%.
Bitcoin price reclaimed the $81,000 level, trading near $81,174 on Sept. 19, up roughly 5% over 24 hours. The move placed BTC below a Glassnode-identified overhead supply band between $83,000 and $86,000, where investors acquired about 1.07 million BTC. Glassnode also highlighted short-liquidation concentration between $82,000 and $86,000 and an options call wall near $85,000. Corporate treasury cost basis sits near $80,500, while spot-fund break-even estimates remain closer to $86,000.
Ether spot ETFs moved in the opposite direction, ending a four-week inflow streak and recording net outflows for the week. That divergence marked a clear rotation in institutional flow momentum between the two largest crypto assets by market capitalization. The next U.S. trading session on Sept. 21 will test whether Bitcoin ETF demand continues and whether Ether’s outflow shift is an isolated dip or a broader reversal.
