Spot Bitcoin ETFs Register Strong Asset Growth and Trading Activity Through 2025

• Spot Bitcoin ETF AUM rose by 124,000 BTC in 87 days, led by BlackRock’s IBIT inflows.
• BlackRock and Fidelity dominated ETF inflows, with no major withdrawals recorded.
• Sector trading volume hit $2.82B, while expense ratios ranged widely across top funds.

Spot Bitcoin exchange-traded funds (ETFs) in the United States have registered large growth in both assets under management (AUM) and trading activity in 2025, with major issuers capturing the majority of new inflows. Since April, the total AUM for spot Bitcoin ETFs, excluding the Grayscale Bitcoin Trust (GBTC), has increased by approximately 124,000 BTC over an 87-day period.

Daily net additions averaged about 1,430 BTC, showing persistent institutional demand for regulated Bitcoin exposure. BlackRock’s iShares Bitcoin Trust (IBIT) accounted for the bulk of these inflows, while other issuers added comparatively smaller amounts.

BlackRock’s IBIT led the market, expanding its holdings from 576,000 BTC to 694,000 BTC since early April, leading to an average daily addition of 1,360 BTC. As of June 28, 2025, IBIT reported $74.53 billion in AUM, daily trading volumes of $2.17 billion, and 1.22 billion shares outstanding.

The fund’s expense ratio stood at 0.25%. Fidelity’s Wise Origin Bitcoin Fund (FBTC) ranked second, managing $21.35 billion in AUM and recording 226.90 million shares outstanding. FBTC posted a daily trading volume of $205.23 million and matched IBIT’s expense ratio.

Data from CryptoQuant, highlighted by industry analyst Axel Adler Jr, showed that, while BlackRock and Fidelity absorbed the largest inflows, issuers such as Bitwise, Ark Invest/21Shares, WisdomTree, Valkyrie, and Franklin contributed steadily but held smaller allocations.

Since early April 2025, the total AUM of spot Bitcoin ETFs (ex-GBTC) has risen from approximately 932 000 BTC to 1 056 000 BTC – an increase of about 124 000 BTC over 87 days, or roughly 1 430 BTC per day. BlackRock’s IBIT has been the main driver, growing from 576 000 BTC to 694… pic.twitter.com/tmqxrA5YsX

— Axel Adler Jr (@AxelAdlerJr) June 28, 2025

The increase in spot in the Bitcoin ETF AUM was faster in the first half of 2024, then stopped growing and regained encouragement in early 2025. According to the cumulative AUM, it exceeded 1,056,000 BTC in June, and no major drawdowns were recorded.

Sector Overview: Trading Volumes and Expense Ratios

The total all-day trading volume across the wider ETF market was $2.82 billion, and the AUM mixture was $135.26 billion. Additional top products were the ARK 21Shares Bitcoin ETF (ARKB) with $4.88 billion in AUM, the Bitwise Bitcoin ETF (BITB) with $4.22 billion, and the Grayscale Bitcoin Trust ETF (GBTC), which it managed, with $19.79 billion and an expense ratio of 1.50%.

The sector featured a range of expense ratios, from BITB at 0.20% to BITO at 5.37%. Price changes for all listed funds on June 28 were negative, reflecting a brief market dip, with daily losses ranging from -0.67% to -0.79%.

Throughout the observed period, sustained allocations and consistent net inflows displayed ongoing institutional confidence in spot Bitcoin ETFs. No major withdrawals occurred, signaling the growing presence of these products within U.S.-regulated financial markets.