Two's Company, IBIT's a Crowd: BlackRock & Fidelity Eat 90% of Bitcoin ETF Lunch 🥄

BlackRock's iShares Bitcoin Trust and Fidelity's Wise Origin Bitcoin Fund have cemented a two-firm grip on U.S. spot bitcoin ETFs, capturing the overwhelming majority of new institutional money in 2026 while smaller issuers recede from the flow conversation. Across multiple high-volume sessions, IBIT and FBTC have not only outpaced competitors but frequently absorbed capital on days rivals bled assets, reinforcing a winner-take-most structure in which scale, liquidity and distribution advantages favor the two largest sponsors.

The pattern surfaced early in the year. On January 14, U.S. spot bitcoin ETFs collectively recorded net inflows of $840.6 million, according to data from Farside Investors. IBIT alone drew $648.4 million, while FBTC pulled in $125.4 million, meaning the two funds together represented more than 90% of that day's allocations. The dynamic repeated on April 17, when total inflows hit $663.9 million; IBIT contributed $284 million and FBTC added $163.4 million, accounting for roughly two-thirds of new money entering the category. On May 1, total inflows reached $629.8 million, with IBIT taking $284.4 million and FBTC taking $213.4 million, a combined nearly $500 million against the broader field.

The concentration has emerged during a difficult stretch for the underlying asset. Bitcoin ($BTC) is down roughly 29% year-to-date, a move that has triggered repeated redemption cycles across the ETF complex. Even within that drawdown, IBIT and FBTC have often acted as stabilizers, attracting inflows on sessions when smaller funds saw outflows, and consistently landing at the top of the daily leaderboard on the year's largest allocation days.

The market structure is leaving other issuers increasingly sidelined. Funds from Ark Invest, Bitwise, VanEck, Franklin Templeton and other launch-day participants now exert minimal influence on aggregate flow direction, a shift that reflects how institutional allocators are consolidating around established counterparties with the deepest balance sheets and broadest distribution rails. The 18-month arc since spot bitcoin ETFs debuted in January 2024 has moved the segment from a crowded, roughly dozen-fund field towards a duopoly that sets the tone for the rest of the cohort.