CustodianCoinbase CustodyFidelity Digital Assets (in-house)
AUM (2026)~$100B+~$25B+
SpreadsTightest in categoryVery tight
Options marketDeepestThinner
IssuerBlackRockFidelity
LaunchedJan 2024Jan 2024
Figures approximate, JUL 2026 — re-verify AUM and spreads at publish. BTC {{ price }}
Category winners
Trading size or writing optionsIBIT
Custody diversificationFBTC
Inside a Fidelity accountFBTC
Buy-and-forget in any brokerageEITHER — FEES IDENTICAL
Tracking qualityBOTH EXCELLENT
OUR VERDICT
Functionally interchangeable for a buy-and-hold investor. Pick IBIT for maximum liquidity and options; pick FBTC if you bank at Fidelity or want your fund’s coins held outside Coinbase’s vaults. Holding both to split custody risk is entirely reasonable. Outside a tax wrapper, compare real bitcoin first — self-custody charges no expense ratio.
Common questions
Why does the custodian matter?
Most US bitcoin ETFs park coins at Coinbase Custody — a single point of concentration for the whole category. FBTC is the major exception.
Is 0.25% expensive?
Mid-pack: BITB (0.20%) and ARKB (0.21%) are cheaper if fee is your only criterion.
Can I convert shares to actual bitcoin?
No — retail holders can only sell for cash. If withdrawable coins matter, buy on an exchange and self-custody.