U.S. bitcoin ETFs drew a reported $457.3 million in net inflows on December 18, 2025, the largest single-day intake in more than a month and a fresh signal of renewed institutional interest in regulated BTC exposure. The move coincided with Bitcoin’s market dominance climbing to 60%, concentrating capital into the flagship asset and reinforcing a market phase in which BTC clearly leads broader crypto risk appetite.
The reported $457.3 million inflow into U.S. spot bitcoin ETFs was led by two headline vehicles: Fidelity’s Wise Origin Bitcoin Fund (FBTC) with $391.5 million and BlackRock’s iShares Bitcoin Trust (IBIT) with $111.2 million. Because the sum of these fund-level contributions exceeds the stated daily total, the figures highlight inconsistencies in reporting windows, aggregation methods or cross-source overlaps that were not reconciled in the available disclosures.
ETF flows, data frictions and macro backdrop
The flow snapshot also noted that some ETF positions traded below their purchase price during the same session, meaning part of the day’s capital was sitting at a mark-to-market loss even as aggregate inflows climbed. This combination of inflows alongside unrealized losses underscores that a subset of allocators is positioning on a longer-term horizon rather than targeting intraday gains.
Bitcoin’s market dominance reaching 60% — a level last seen on November 14 when BTC was near $100,000 — signals a renewed tilt toward large-cap safety within crypto rather than broad risk dispersion. Historically, elevated dominance has corresponded with capital rotating into Bitcoin at the expense of smaller tokens, suppressing altcoin performance while reinforcing demand for bitcoin-focused products.
Macro catalysts remain in play, with market participants pointing to upcoming interest-rate decisions from the Bank of England and European Central Bank and inflation data in the U.S. and Japan as potential volatility drivers. These policy and data releases are likely to influence ETF flows and price dynamics as institutional investors reassess rate paths, liquidity conditions and the role of Bitcoin within multi-asset portfolios.
For miners, rising institutional demand via ETFs can influence short-term treasury and selling strategies by tightening perceived future supply and changing incentives around when and how production is monetized. For product and compliance teams, the day’s flows highlight the need for consistent reporting standards, clear time-stamping and transparent valuation methodologies to reduce confusion when aggregated and fund-level figures diverge.