According to the source, BlackRock’s iShares Bitcoin Trust (IBIT) is already the firm’s most profitable ETF by fee revenue, surpassing older iShares funds as AUM and sponsor fees scale with BTC. Source: the source. IBIT charges a 0.25% sponsor fee and holds spot Bitcoin with Coinbase Custody, aligning revenue directly with BTC price and net inflows—key metrics traders can monitor for liquidity signals. Source: iShares Bitcoin Trust (IBIT) prospectus, BlackRock; SEC EDGAR. IBIT operates with daily creations and redemptions via authorized participants, making its AUM, creation activity, and premium/discount to NAV useful signals for BTC spot demand and liquidity during U.S. trading hours. Source: iShares Bitcoin Trust (IBIT) prospectus, BlackRock. Traders can track AUM, daily flows, and NAV data on the iShares IBIT fund page to assess intraday liquidity conditions for BTC and adjust exposure timing. Source: iShares IBIT fund page, BlackRock.