Fidelity FBTC vs ARK 21Shares ARKB: Comparing Bitcoin ETFs

The $2.4 billion inflow surge

The week ending September 25, 2026, brought $2.4 billion in net inflows to U.S. spot Bitcoin ETFs. This inflow amount was the highest since the week ending October 10, 2025, when net inflows totaled $2.7 billion and Bitcoin hit a new all-time high of $126,296. Monday, September 21, saw $999 million in net inflows, which was the ninth largest one-day net inflow since the funds launched in January 2024. The daily inflow amounts dropped from $714.7 million on Tuesday to $347 million on Wednesday, $190.6 million on Thursday, and $134.5 million on Friday. On Monday, ARKB received $289.1 million and FBTC received $238.8 million. Bitcoin price reached $87,395 on that Monday.

These inflows pushed 2026 net flows to about $934 million, which offsets the $5.8 billion in net outflows recorded in mid-July 2026. The Monday surge was driven by heavy demand, although daily amounts fell throughout the week. Bitcoin price moved above the $87,000 resistance level on September 21 before falling back. Traders watched the $82,000 level for support as the price dropped toward $82,900 on September 24. The $2.4 billion total reflects a recovery after the market lost $746 million in mid-September due to a Fed interest rate hike and Senate action against the CLARITY Act. The Monday total of $999 million was the largest since October 2025, and it came alongside $270 million in spot Ether ETF inflows. Approximately $919 million in crypto short positions were liquidated during the surge.

Fee wars and structural differences

ARKB has a lower expense ratio than FBTC. The expense ratio for ARKB is 0.21%, while the expense ratio for FBTC is 0.25%. For a $10,000 investment, the fee difference over ten years is $40. For a $50,000 IRA position held for 20 years with a 15% annual return, the difference in fees reaches about $3,000. FBTC holds $15.5 billion in assets, which is more than five times the $2.87 billion held by ARKB. This size difference gives FBTC better trading depth and tighter bid-ask spreads. You know that scale is a primary driver for liquidity in these products.

Fidelity manages its holdings through Fidelity Digital Assets. ARKB uses Coinbase Custody. The competition over costs is visible in other markets. In Europe, WisdomTree Physical Bitcoin ETP fees fell from 0.95% to 0.35%. The Invesco Physical Bitcoin ETP fee dropped from 0.99% to 0.39%. VanEck also plans to be more aggressive with marketing in Europe. The US price wars have settled around 30 basis points. Grayscale’s management fee is 1.5%.

Performance and volatility

Performance between the two funds is nearly identical. ARKB had a total return of -26.22% over the trailing twelve months, while FBTC had -26.25% over the same period. Since January 2024, FBTC has compounded at 24.12% per year, and ARKB has compounded at 24.10% per year. Neither fund has established a distribution history or reported a yield. Both funds track Bitcoin with a beta near 1.88. A 10% move in Bitcoin results in an 18.8% move in the price of either ETF.

The volatility for ARKB was 37.48% over the last year, while FBTC volatility was 38.25%. The maximum drawdown for both funds was roughly 7% over the same period. Both funds experienced a maximum drawdown duration of 359 days. Bitcoin reached a weekly high of $66,891 during the period of these inflows. The price also saw a drop of 3% from Wednesday to Friday prices. Bitcoin is down 4% in 2026 and down 23% from a year prior. Analysts mention a potential cycle low near $38,000 to $39,000. The average cost basis for Bitcoin is about $81,722. Bitcoin price also remains sensitive to the 60% market dominance level.

The final verdict

I recommend ARKB for investors who want the lowest expense ratio. I recommend FBTC for investors who want institutional scale and in-house custody. The choice depends on if you prefer the ARK ecosystem or Fidelity infrastructure. FBTC leads in size, while ARKB leads in cost.

The decision often depends on institutional preference. FBTC offers the depth of a $15.5 billion fund. ARKB offers a 0.21% fee. You should check if your brokerage integrates better with Fidelity. Will the US fee war force another round of cuts for the major providers?