Investors were more cautious and polarized in the lead-up to the launch of an Ethereum ETF in the United States, in contrast to the widespread frenzy that preceded the launch of a Bitcoin ETF. A major concern for some investors is that the SEC has ruled out the "staking" mechanism, a key feature on the Ethereum blockchain. Pledging allows Ethereum users to earn rewards by locking up their ether to help protect the network. Rewards or proceeds come in the form of newly issued ether and a portion of the network's transaction fees. Under the current architecture, the SEC will only allow ETFs to hold regular, uncollateralized ether. "Institutional investors looking at Ethereum know that there is a yield on staking," said Mr. McLurg, analyst at CoinShares. "It's like a bond manager saying, I'm going to buy bonds but I don't want to earn interest, which is the opposite of what you were looking for when you bought bonds." Mr. McLurg believes investors will continue to stake Ethereum outside of ETFs and earn a yield, rather than paying fees and holding Ethereum in ETFs.