US-based spot bitcoin exchange-traded funds (ETFs) continued their upward trajectory, recording their 12th consecutive day of positive net inflows on May 30th. This marks the longest stretch of inflows since late February, signaling a renewed interest from investors in these investment products.

The total daily net inflow for spot bitcoin ETFs amounted to $28.32 million, with BlackRock's iShares Bitcoin Trust (IBIT) leading the pack with $24.5 million in inflows, solidifying its position as the largest spot bitcoin ETF by net asset value. This surge in IBIT's popularity comes after it surpassed Grayscale's Bitcoin Trust (GBTC) on the preceding day.

Meanwhile, Grayscale's GBTC experienced net outflows of $31 million, further widening the gap between the two top competitors in the spot bitcoin ETF market. This discrepancy in inflows suggests a preference among investors for ETFs offering direct exposure to bitcoin, as opposed to GBTC's trust-based structure.

Fidelity Digital Assets' Wise Origin Bitcoin Fund (FBTC) also saw significant inflows of $18 million, securing its position as the third-largest spot bitcoin ETF. Several other prominent firms, including Bitwise, Ark Invest, 21Shares, Invesco, Galaxy Digital, and WisdomTree, also reported positive inflows, albeit in smaller amounts.

In total, US-based spot bitcoin ETFs saw net inflows exceeding $2 billion over the past 12 days, bringing the year-to-date total to $13.76 billion, indicating a notable surge in institutional investment in bitcoin since mid-May.

In a separate development, BlackRock, the world's largest asset manager, has filed an amended registration statement for its proposed Ethereum ETF, the iShares Ethereum Trust (ETHA). This move aligns with the increasing trend of firms seeking to introduce and trade Ethereum-based products.

The amended filing discloses information about BlackRock's seed capital investor and confirms the ticker symbol for the ETF as "ETHA." While the US Securities and Exchange Commission (SEC) has initiated discussions with issuers regarding their S-1 forms, the timeline for approval remains uncertain. Industry analysts anticipate the process could take several weeks, with a potential launch window between late June and early July.

Eric Balchunas, a Bloomberg ETF analyst, views BlackRock's amended S-1 filing optimistically, seeing it as a positive indication for the future launch of Ethereum ETFs.