U.S. spot Bitcoin exchange-traded funds attracted $3.4 billion in net inflows across a six-week stretch through early May, marking the longest continuous inflow streak since mid-2025. The demand reinforced the ETF wrapper as a preferred institutional on-ramp to Bitcoin and helped absorb a meaningful share of available market supply in April.
April was the strongest month in the current inflow cycle, with market tallies ranging from $1.97 billion to $2.44 billion in net ETF demand. That represented a clear acceleration from March, when inflows were estimated between $1.32 billion and $1.37 billion.
BlackRock Leads a Concentrated ETF Flow
BlackRock’s iShares Bitcoin Trust dominated April’s activity, with IBIT accounting for roughly $1.71 billion of the higher monthly estimate. That represented about 70% of the $2.44 billion total, underscoring how concentrated institutional Bitcoin exposure has become inside the largest ETF products.
Fidelity’s Wise Origin Bitcoin Fund added roughly $213.4 million in April inflows, giving the month a second major institutional channel but leaving BlackRock clearly ahead. For allocators and trading desks, that concentration raises practical questions around execution, liquidity and provider-level flow tracking.
Weekly data showed a steady but smaller run than the 2025 inflow surge. The week ending April 17 delivered about $996.4 million, while weekly inflows since April 2 averaged roughly $568 million.
By comparison, the seven-week streak that ended on July 25, 2025 brought in $10.58 billion at an average of $1.51 billion per week. The current streak has been notable for continuity, but not for the same weekly intensity as that earlier institutional wave.
ETF Buying Absorbs a Large Share of New Supply
The April flows materially tightened Bitcoin’s available supply. Using the higher $2.44 billion estimate and average prices in the mid-$70,000s, ETFs appear to have added about 32,000 BTC to their holdings during the month.
That accumulation equaled roughly one-fifth of the year’s projected miner issuance of 164,000 BTC. When combined with corporate purchases such as MicroStrategy’s April acquisition of 34,164 BTC for about $4.1 billion, institutional demand outpaced new supply by a wide margin.
Price action reflected the supply pressure. An eight-day ETF inflow streak totaling about $2.1 billion coincided with a 12% Bitcoin rally from roughly $68,000 to $77,000, before the market briefly moved above $80,000 in early May.
Heavy ETF accumulation can remove spot liquidity from the open market, increasing slippage risk for large OTC transactions and making execution more sensitive to weekly subscription patterns.
The product concentration also changes risk management. If ETF assets grow toward the $180 billion to $220 billion range projected in reporting for year-end 2026, regulated wrappers could become an even larger force in Bitcoin price discovery across both spot and derivatives venues.
The recent streak shows capital continuing to rotate into products that simplify custody, reporting and compliance. That reduces some counterparty complexity for institutions, but it also makes Bitcoin liquidity more dependent on ETF demand cycles, especially when flows are concentrated in a small number of dominant issuers.