U.S. Spot Ethereum exchange-traded funds saw $533.9 million in net inflows on Tuesday, marking the third-largest daily inflow since their launch.

SoSoValue data shows that BlackRock's iShares Ethereum Trust (ETHA) recorded $426.2 million in net inflows on Tuesday, while Grayscale’s Ethereum Mini Trust saw $72.6 million. Fidelity's ETF also attracted $35.0 million.

Tuesday's inflows into the spot ether ETFs marked the third-largest single-daily inflow since their inception, trailing the $726.7 million recorded last Wednesday and $602.0 million last Thursday.

The ETF inflows reflect a growing investor appetite for ether. Vincent Liu, CIO of Kronos Research, said that with BTC dominance dipping and macro conditions steady, "ETH's momentum looks set to sustain in the mid-term as long as these factors hold."

Nick Ruck, director of LVRG Research, said that institutions appear to remain bullish on Ethereum, with spot ETF inflows reaching record highs, "as reserve strategies for the digital asset showcase a second opportunity for investors who missed out on Bitcoin's historic rise."

Ethereum has become a go-to asset for companies adopting a crypto treasury strategy. For example, marketing and software firm SharpLink Gaming shifted its focus to accumulating ether after announcing its Ethereum treasury strategy in May.

Meanwhile, spot bitcoin ETFs saw $67.9 million in net outflows on Tuesday, following outflows of $131.3 million the previous day.

"We're seeing a familiar rotation from Bitcoin to Ethereum, often a precursor to broader altcoin momentum," said Min Jung, research analyst of Presto. "Bitcoin has rallied significantly this year, and for investors who feel they've 'missed' the BTC trade or are looking for the next opportunity, Ethereum is becoming the natural next step."