Bitcoin and Ethereum ETFs Record Strongest Month of 2025 as Inflows Outpace $3.6B

Monthly net inflows into U.S. Bitcoin ETF products have exceeded $3.6 billion as of May 20, 2025. The surge marks a complete reversal of the earlier $4.6 billion outflows between February and March.

Net monthly inflows into U.S. Bitcoin ETF products have exceeded $3.63 billion as of May 20, according to the latest estimates. This marks a complete reversal from the $4.62 billion outflows seen between February and March.

As Ethereum (ETH) funds also posted their best month of 2025 in May, both major cryptocurrency ETFs are in the spotlight.

Bitcoin ETF Post Strongest Month of 2025

Bitcoin ETFs continue to register strong momentum, with an estimated $329.02 million in daily net outflows on May 20. Weekly flows are at $996.46 million, showcasing sustained demand.

After April’s estimations placed net monthly inflows at $2.97 billion, new figures show that in the third week of May alone, Bitcoin ETFs are poised to register a staggering $3.63 billion in net inflows.

Among the key players, BlackRock’s iShares Bitcoin Trust (IBIT) is a standout performer, adding a substantial $287.45 million in a single day. It now holds $67.9 billion in net assets and has collected $46.15 billion in cumulative net inflows.

The iShares fund has consistently maintained its lead throughout 2025, rendering it the best-performing Bitcoin ETF.

Meanwhile, Fidelity’s Wise Origin Bitcoin Fund (FBTC) saw a more modest $23.26 million in daily inflows, bringing its total to $11.81 billion. FBTC manages $21.33 billion in net assets.

Mid-Sized Bitcoin ETF Show Steady Performance

Turning to the mid-sized Bitcoin ETFs, the ARK 21Shares Bitcoin ETF (ARKB) reported $6.36 million in net inflows on May 20. Its consistent performance underscores the increasing support for a broader range of Bitcoin ETF products.

The Grayscale Bitcoin Mini Trust also saw a strong inflow of $6.16 million on the same day.

Further down the list, Bitwise Bitcoin ETF (BITB) reported $5.78 million in net inflows, showcasing stable momentum throughout the month. Despite their smaller size compared to the flagship iShares and Fidelity funds, these mid-tier Bitcoin ETFs are collecting an impressive amount of capital.

Together, they are a testament to the bullish sentiment that persists across the sector.

With such strong demand, Bitcoin ETFs have become a central vehicle for crypto-related exposure in traditional finance. The mind-boggling volume signals the significant participation of institutional investors.

As the market remains highly active, Bitcoin ETF performance continues to surpass expectations.

Ethereum ETFs Record Best Month of the Year

May has also seen substantial inflows into Ethereum ETF products, with estimates placing the total at $108.58 million. This surpasses January’s total of $101.16 million, making it the best month of 2025 so far for ETH funds.

On May 20 alone, ETH ETFs gained an estimated $64.89 million in daily net inflows, highlighting the strong and sustained demand.

Among the key players, BlackRock’s iShares Ethereum Trust (ETHA) is the standout performer, with an estimated $45.04 million in net inflows on the day. The fund now holds an estimated $3.24 billion in net assets and has an estimated cumulative net inflow of $4.32 billion.

Throughout 2025, ETHA has consistently maintained its position as the dominant Ethereum ETF.

Fidelity’s FETH is another notable fund, with an estimated $19.85 million in net inflows on May 20. This brings FETH’s total to an estimated $1.43 billion in cumulative net inflows, and the fund is estimated to hold $1 billion in net assets.

As interest in Ethereum ETFs continues to grow, these funds are playing an increasingly crucial role in facilitating accessible investment in the major cryptocurrency.

With both Bitcoin ETFs and Ethereum funds performing exceptionally well and setting new records, it’s clear that investors are shifting towards these innovative investment products in record numbers.

May is set to be an outstanding month for both BTC and ETH ETF performance.