Which ETF has a lower expense ratio, IBIT or ARKB?

ARKB has the lower expense ratio at 0.21% vs 0.25% for IBIT.

Which ETF is larger by assets under management, IBIT or ARKB?

IBIT is larger by AUM. IBIT has approximately $46.5B in assets versus $2.1B for ARKB (based on most recent available data).

Can I hold both IBIT and ARKB in my portfolio?

Yes. Both IBIT and ARKB can be held simultaneously through most brokerage accounts. However, since both track the spot price of Bitcoin, holding both in large quantities results in concentrated and highly correlated exposure. Investors typically choose one spot Bitcoin ETF rather than diversifying across multiple to keep costs low.

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IBIT vs ARKB

Head-to-head Bitcoin ETF comparison - expense ratios, AUM, performance, and more

Quick Answer

ARKB has the lower expense ratio at 0.21% versus 0.25%. iShares's IBIT is roughly 22x larger by assets ($46.5B vs $2.1B) and trades about 13x the daily volume. ARK 21Shares's ARKB uses Coinbase Custody (primary, with BitGo added) for Bitcoin custody, while IBIT uses Coinbase Custody.

IBIT

BlackRock iShares Bitcoin Trust ETF

IssueriShares

Expense Ratio0.25%

AUM$46.5B

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ARKB

ARK 21Shares Bitcoin ETF

IssuerARK 21Shares

Expense Ratio0.21%

AUM$2.1B

View full profile

At a Glance

Lower Fee

ARKB

Larger AUM

IBIT

More Liquid

IBIT

Best YTD

Tied

Full Comparison

Metric	IBIT	ARKB
Expense Ratio	0.25%	0.21% Winner
AUM	$46.5B Winner	$2.1B
Price	$36.80	$21.54
YTD Return	-27.76% Tie	-27.69% Tie
1-Year Return	-44.93% Tie	-44.91% Tie
Avg Daily Volume	46.7M Winner	3.6M
Custodian	Coinbase Custody	Coinbase Custody (primary, with BitGo added)
Issuer	iShares	ARK 21Shares
Inception Date	Jan 5, 2024	Jan 11, 2024
Exchange Listed	Nasdaq	Cboe BZX Exchange
SEC Registered	Yes	Yes

Key Differences

Different Custodians

IBIT holds its Bitcoin with Coinbase Custody, while ARKB uses Coinbase Custody (primary, with BitGo added). Custodian choice affects your exposure to counterparty risk and the operational security model protecting the fund's Bitcoin.

Liquidity Gap

IBIT trades significantly more volume on average, making it easier to enter and exit large positions with tighter bid-ask spreads. ARKB is less liquid and can see wider spreads during volatile sessions.

Which Is Right For You?

IBIT is best for:

U.S. investors seeking low-cost spot Bitcoin exposure through a major asset manager

ARKB is best for:

U.S. investors seeking low-cost direct Bitcoin exposure through a dual-custodied spot ETF

21Rates Take

IBIT and ARKB charge nearly identical expense ratios, but they differ in issuer profile. IBIT is backed by BlackRock, the world's largest asset manager, while ARKB is a joint product from ARK Invest and 21Shares, pairing Cathie Wood's innovation brand with 21Shares' deep crypto ETP expertise. IBIT dominates on AUM and trading volume by a wide margin. ARKB appeals to investors who already hold ARK funds and want a Bitcoin ETF that fits their existing portfolio narrative. On pure cost and liquidity, these two are essentially neck and neck.

Reviewed by 21Rates Editorial on Jul 20, 2026

Frequently Asked Questions

What is the difference between IBIT and ARKB?

IBIT is issued by iShares and charges a 0.25% expense ratio, while ARKB is issued by ARK 21Shares at 0.21%. Both are spot Bitcoin ETFs that hold physical Bitcoin. They differ in issuer, custody arrangements (IBIT uses Coinbase Custody; ARKB uses Coinbase Custody (primary, with BitGo added)), and overall fund scale.

Which has the lower expense ratio, IBIT or ARKB?

ARKB has a lower expense ratio at 0.21% versus 0.25% for IBIT.

Which ETF has more assets under management?

IBIT is the larger fund by AUM at $46.5B versus $2.1B for ARKB.

Can I hold both IBIT and ARKB at the same time?

Yes. Both funds can be held in most brokerage accounts simultaneously. However, since both track Bitcoin, holding both creates highly correlated exposure. Most investors choose one fund to keep costs and complexity low.

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Market data (price, AUM, volume, returns) is updated up to 3 times daily from live market sources. Expense ratios and fund details are sourced from fund prospectuses and issuer disclosures.

Data as of Aug 8, 2026.

This comparison is for informational purposes only and does not constitute investment advice. Bitcoin ETFs are subject to market risk including the potential loss of principal. Past performance does not guarantee future results.