The bitcoin ETF market is undergoing a significant transformation, with BlackRock and Fidelity's funds dominating the landscape. This shift has left smaller issuers struggling to maintain relevance, as institutional investors increasingly concentrate their allocations in the largest and most liquid vehicles. The trend is particularly evident during periods of market volatility, where the behavior of BlackRock's iShares Bitcoin Trust (IBIT) and Fidelity's Wise Origin Bitcoin Fund (FBTC) often determines the overall direction of the market. This concentration has emerged during a challenging year for bitcoin and the broader crypto ETF market, with bitcoin down roughly 29% year-to-date. The dominance of these two funds is not surprising, given their relationships with thousands of wealth-management platforms and their ability to act as a stabilizing force during periods of market stress. The trend is also driven by the fact that many of the largest buyers of bitcoin ETFs are financial advisers, registered investment advisers, hedge funds, family offices, pension consultants, and institutional asset allocators, who prioritize liquidity, trading volume, and issuer reputation over the underlying bitcoin exposure itself. As a result, many allocators view IBIT and FBTC as the default options for gaining bitcoin exposure. The flip side is that smaller issuers are struggling to remain relevant, with funds like Franklin Templeton's EZBC, VanEck's HODL, Valkyrie's BRRR, and WisdomTree's BTCW recording daily flows measured in single-digit millions of dollars. This concentration has significant implications for the future of the bitcoin ETF market, suggesting that it is entering a new phase where scale, liquidity, and distribution will drive investor decisions. The prediction markets platform Kalshi has also introduced new measures to combat insider trading and market manipulation, further highlighting the importance of scale and liquidity in the market.