Bitcoin ETF Comparison: Spot ETFs, Fees, and AUM Compared

US Spot Bitcoin ETFs at a Glance

The SEC approved 11 spot Bitcoin ETFs on January 10, 2024, and trading began on January 11. Within their first year, these funds collectively attracted over $56 billion in net inflows, making it the most successful ETF launch category in history. As of March 2026, combined assets under management sit at approximately $91 billion.

The Grayscale Bitcoin Mini Trust (ticker: BTC) launched later on July 31, 2024, seeded with roughly 10% of GBTC's Bitcoin holdings. Including this fund, there are now 12 US-listed spot Bitcoin ETFs. The following table provides a high-level comparison of every fund.

Fee Comparison

Expense ratios range from 0.15% to 1.50%, a 10x difference that compounds significantly over time. Most funds have converged on the 0.19%–0.25% range, but two outliers stand out: Grayscale's original GBTC at 1.50% (the most expensive by far) and the Grayscale Mini Trust at 0.15% (the cheapest permanent fee).

VanEck's HODL is currently the only zero-cost option: the sponsor fee of 0.20% is fully waived through July 31, 2026, or until AUM exceeds $2.5 billion, whichever comes first. All other promotional fee waivers from launch have expired.

On a $100,000 position held for five years, the difference between GBTC's 1.50% fee and EZBC's 0.19% fee exceeds $6,500 in cumulative costs (assuming flat Bitcoin price). For a deeper analysis of how fees affect long-term returns, see our crypto exchange fee comparison.

Note: GBTC's high fee is a legacy of its original closed-end trust structure. Despite losing billions in outflows, GBTC still generates roughly $223 million per year in fee revenue: more than all other spot Bitcoin ETFs combined.

AUM Rankings and Market Share

BlackRock's IBIT dominates with approximately 77% of total spot Bitcoin ETF assets. This concentration reflects BlackRock's distribution advantages: IBIT is available on every major brokerage platform, has the tightest bid-ask spreads, and consistently leads daily trading volume. IBIT accumulated $62.88 billion in cumulative net inflows since launch.

Fidelity's FBTC and the legacy Grayscale GBTC round out the top three. GBTC's $14.9 billion AUM is notable given that the fund has experienced persistent outflows as investors rotate into cheaper alternatives. Below GBTC, a cluster of mid-tier funds (ARKB, BITB, and the Grayscale Mini Trust) each hold $3B to $4B. The remaining five funds each hold under $1.5 billion.

For context on how ETF inflows have shaped Bitcoin's market structure, see our research on the impact of Bitcoin ETFs on adoption.

Custody and Structure

A critical but often overlooked dimension of spot Bitcoin ETFs is custody: who holds the actual Bitcoin backing each fund. Coinbase Custody Trust Company serves as custodian for 8 of the 11 original ETFs, creating significant concentration risk. Several issuers have responded by adopting multi-custodian arrangements.

IBIT uses both Coinbase and Anchorage Digital Bank. BRRR (CoinShares) was the first fund to add a second custodian, bringing on BitGo Trust Company alongside Coinbase. ARKB and HODL have also adopted multi-custodian models. Fidelity's FBTC is unique: it uses Fidelity Digital Assets for custody, making it the only major spot Bitcoin ETF that does not rely on Coinbase at all.

All spot Bitcoin ETFs are structured as grantor trusts. They hold physical Bitcoin (not futures contracts), and each share represents a fractional claim on the trust's BTC holdings. None of the funds allow in-kind creation and redemption: all authorized participant transactions settle in cash, which introduces minor tracking error compared to the underlying spot price.

For investors who prefer to hold Bitcoin directly rather than through a trust structure, our guide on Bitcoin custody solutions covers cold storage, hot wallets, and multi-signature setups.

Trading Volume and Liquidity

Daily trading volume matters for investors who need tight spreads and reliable execution. IBIT consistently leads with the highest daily volume among all spot Bitcoin ETFs, often exceeding the combined volume of all other funds. FBTC holds a steady second place, followed by GBTC in third.

Mid-tier funds like ARKB and BITB trade with reasonable liquidity for most retail investors but may show wider spreads during volatile sessions. The smaller funds (BTCW, BRRR, EZBC, BTCO) typically have lower volume, which can result in marginally higher trading costs for large orders.

For institutional-size allocations, IBIT and FBTC are the practical choices. Retail investors with smaller positions may find that any of the top-five funds provide adequate liquidity.

How to Choose a Bitcoin ETF

Selecting a spot Bitcoin ETF involves balancing fees, liquidity, custodial risk, and issuer reputation. Here is a practical framework:

If cost is your top priority: the Grayscale Mini Trust (BTC) at 0.15% offers the lowest permanent expense ratio. VanEck's HODL is effectively free until its waiver expires in July 2026, but its ongoing fee reverts to 0.20% afterward.

If liquidity and ease of trading matter most: IBIT is the clear winner. It has the tightest spreads, highest volume, and widest brokerage availability. FBTC is the strongest alternative.

If custody diversification concerns you: FBTC uses Fidelity's own custody infrastructure. IBIT and BRRR use multi-custodian models. These options reduce single-custodian concentration risk.

If you already hold GBTC: consider whether the 1.50% annual fee justifies staying. Selling triggers a taxable event, but the fee savings from switching to a 0.20% fund could exceed the tax cost within a few years, depending on your situation.

ETFs vs. Direct Bitcoin Ownership

Spot Bitcoin ETFs provide convenient exposure through a traditional brokerage account, but they are not equivalent to holding Bitcoin directly. ETF holders do not control private keys, cannot transact on-chain, and cannot use their Bitcoin in layer 2 protocols or for dollar-denominated payments.

Direct self-custody gives holders full sovereignty over their Bitcoin. They can send, receive, and use BTC without intermediaries. Protocols like Spark extend this capability by enabling fast, low-cost transfers and stablecoin access natively on Bitcoin, something ETFs cannot offer.

The tradeoff: self-custody requires managing seed phrases, key management, and security practices. ETFs abstract away these responsibilities but introduce counterparty risk, custody concentration, and ongoing fees.

Frequently Asked Questions

What is the cheapest Bitcoin ETF?

The Grayscale Bitcoin Mini Trust (BTC) has the lowest permanent expense ratio at 0.15%. VanEck's HODL is effectively free until July 31, 2026, thanks to a full sponsor fee waiver, but its standard fee is 0.20%. After HODL's waiver expires, the Grayscale Mini Trust becomes the cheapest option. Franklin Templeton's EZBC at 0.19% is also among the lowest-cost funds.

Which Bitcoin ETF has the most assets?

BlackRock's iShares Bitcoin Trust (IBIT) holds approximately $70.6 billion in assets, representing roughly 77% of all spot Bitcoin ETF AUM. IBIT accumulated $62.88 billion in cumulative net inflows since its January 2024 launch, making it the fastest-growing ETF launch in history regardless of asset class.

Is GBTC worth the higher fee?

For most investors, no. GBTC charges 1.50% annually, which is 6x to 10x more expensive than competing funds that hold the exact same asset. Investors who purchased GBTC before the ETF conversion may face a taxable event upon selling, which is the primary reason some holders remain. Grayscale launched the Mini Trust (BTC) at 0.15% as a lower-cost alternative for cost-conscious investors.

Do Bitcoin ETFs hold actual Bitcoin?

Yes. All US spot Bitcoin ETFs hold physical Bitcoin in custody. They are not futures-based products. Each share represents a fractional claim on the trust's Bitcoin holdings. However, creation and redemption happens in cash (not in-kind), meaning authorized participants exchange dollars rather than BTC when creating or redeeming shares.

Who is the custodian for most Bitcoin ETFs?

Coinbase Custody Trust Company serves as primary custodian for 8 of the 11 original spot Bitcoin ETFs. This concentration has prompted several issuers to adopt multi-custodian models: IBIT added Anchorage Digital Bank, BRRR added BitGo, and others have followed. Fidelity's FBTC is the only major fund using its own custody solution (Fidelity Digital Assets), making it the most independent from a custodial perspective.

Can I buy Bitcoin ETFs in a retirement account?

Yes. Spot Bitcoin ETFs trade on regulated US exchanges and are available in standard brokerage accounts, IRAs, and 401(k) plans (where the plan administrator permits). This is one of the primary advantages of ETFs over direct Bitcoin ownership: tax-advantaged account access. Holding IBIT or FBTC in a Roth IRA, for example, allows Bitcoin exposure with tax-free growth.

What is the difference between GBTC and the Grayscale Mini Trust?

Both are Grayscale products holding physical Bitcoin, but they differ in cost and origin. GBTC charges 1.50% and was converted from a closed-end trust that originally launched in 2013. The Grayscale Bitcoin Mini Trust (BTC) launched on July 31, 2024 with a 0.15% expense ratio, seeded with approximately 10% of GBTC's Bitcoin holdings. The Mini Trust was designed specifically as a low-cost alternative for investors who wanted Grayscale's brand without the premium fee.

This tool is for informational purposes only and does not constitute financial advice. AUM figures, expense ratios, and fee waivers are approximate and based on publicly available data as of March 2026. Fund terms can change: always verify current fees and holdings on the issuer's official website before making investment decisions.