Oct 2 (Reuters) - Three U.S. investment managers on Monday launched the first futures-based exchange traded funds (ETFs) tied to the value of ether, the world's second-largest cryptocurrency.

The six new funds by ProShares, VanEck and Bitwise Asset Management allow investors to take positions in exchange-traded products based on ether for the first time.

Collectively, the six funds saw trading volumes total $1.92 million in their first day of trading, according to data from LSEG. The single largest fund, the ProShares Ether Strategy ETF saw trading valued at $878,560.

The debuts of the futures-based products come even as the U.S. Securities and Exchange Commission (SEC) continues to weigh whether to approve ETFs tied to spot prices of bitcoin and, potentially, ether and other cryptocurrencies.

"This is a logical next step for regulators and asset managers," said Aisha Hunt, a principal at Kelley Hunt & Charles LLC, who advises clients in the ETF market.

"The fact that these are tied to futures contracts regulated by the CFTC likely made the SEC more receptive," she said, referring to the Commodity Futures Trading Commission.

In contrast, the SEC has denied all spot bitcoin ETF applications, saying applicants have not shown they can protect investors from market manipulation.

It has been almost exactly two years since the first ETF designed to track bitcoin futures, the ProShares Bitcoin Strategy ETF, made its blockbuster debut. On its first day, trading in that fund was valued at more than $130 million.

The six new funds vary by strategy, structure and cost. The ProShares Ether Strategy ETF, the VanEck Ethereum Strategy and the Bitwise Ethereum Strategy ETF offer pure exposure to ether futures contracts traded on the Chicago Mercantile Exchange. The other three will blend exposure to ether with bitcoin using various methodologies.

The VanEck fund has the lowest expense ratio, which stands at 0.66%, compared to 0.85% for the two Bitwise funds and 0.95% for the ProShares ETFs, and is the only one of the six to be structured as a C-corporation.

That likely means that investors will pay a lower overall tax rate on profits from the ETF, VanEck noted, since a portion can be distributed as dividends rather than capital gains.

"Fees will likely be the big differentiator between these funds," says Roxanna Islam, head of sector and industry research at VettaFi.

More ETFs tied to ether futures are expected. Trading is set to begin on Tuesday in the re-designed Valkyrie Bitcoin and Ether Strategy. Valkyrie Funds announced on Monday it had completed the conversion of its bitcoin-only ETF into a dual cryptocurrency product. Ahead of the conversion, trading volume in that ETF totaled $4.57 million.

"The launch of an ether futures ETF shouldn't be read as a tea leaf that the SEC has changed its position on spot bitcoin ETFs," said Hunt.

Those "will continue to face significant regulatory headwinds," she said.

(Reporting by Bansari Mayur Kamdar in Bengaluru; Editing by Shweta Agarwal and Sonali Paul)