Options traders are turning their attention to long-term bullish bets on the cryptocurrency ether, as some anticipate that an ether-based exchange-traded fund (ETF) product will likely follow the launch of the first bitcoin futures-based ETF in the U.S.Data reveal a growing demand for long-dated, out-of-the-money (OTM) call options on ether – bullish bets with strike prices well above the spot market price of the cryptocurrency.A strong purchase activity was captured on ether’s $15,000 calls expiring March 25, 2022, according to Singapore-based trading firm QCP Capital. That’s a far cry from current spot prices; ether traded above $4,000 in the past three days, following bitcoin’s surge to nearly $67,000.Markets’ “long-term attention seems to be shifting from BTC to ETH with potential ETH ETF release after BTC [ETF in the U.S.], coupled with ETH 2.0 catalyst,” QCP Capital wrote in its Telegram channel on Tuesday.Data provided by crypto derivatives exchange Deribit shows that call options with a strike price at $15,000 have the highest open interest for all options expiring in March 2022.Genesis Volatility, another data provider, said while the flows for the $15,000-strike calls have been a mix of buyers and sellers, the initial transactions at this strike price started with a buy of roughly 700 contracts on Oct. 15. At the time, open interest was at roughly 8,000 contracts. There were about 40,000 contracts open interest for the $15,000-strike March calls as of Wednesday.“The mix in flow is good,” Greg Magadini, co-founder and CEO of Genesis Volatility, told CoinDesk. “It means there’s a real two-way market here and people hold both views regarding $15,000 being possible.”Bitcoin’s surged to a new all-time high earlier Wednesday during trading hours in the U.S, after the successful debut of the first U.S. bitcoin futures-based ETF. Some market participants have hoped that an ether ETF may be approved, boosting ether’s price, too.There are at least five known applications in the U.S. for ether-based ETFs including two ether futures-based products by fund manager VanEck (The Ethereum Strategy ETF) and ProShares (Ether Strategy ETF).“With the launch of the bitcoin futures ETF, it has become a certainty that an ether ETF of the same kind can’t be that far off,” Stefan Coolican, president and chief financial officer at investment firm Ether Capital, said. “Both cryptos are decentralized and ether is no more complex than bitcoin in that regard from a regulatory perspective.”A few speculate that an ether-based ETF will launch as soon as this year.“An ether ETF will definitely launch this year and will definitely be bullish for ether,” Trey Griggs, CEO of crypto market GSR’s U.S. arm, said in a written response. “The robust interest in the BTC ETF has again sparked rapid fire conversations in the investment management community about products that track a broad array of altcoins.”Data show there are traders willing to bet this will happen. Over the past three days, institution-focused, over-the-counter desk Paradigm noticed that their clients’ flows continued to lean “bullish” for ether, with particularly high volumes on both outright and call spread trades for call options expiring November, December and March 2022.Options are hedging instruments that give the purchaser the right but not the obligation to buy the underlying asset at a predetermined price on or before a specific date. A call option gives the right to purchase, and the put offers the right to sell.“What we see are bullish bets for a move higher into year end and March of next year,” Patrick Chu, director of institutional sales and trading at Paradigm, told CoinDesk.QCP also noted that long-term implied volatility (IV) has rallied more than 10% since the past weekend, with a strong put-call skew – the cost of puts relative to calls – favoring calls. Implied volatility is investors’ expectations of price turbulence over a specific period. A higher implied volatility results from greater demand for options and vice versa. That translates into higher prices for both put and call options.Data from Skew shows that the three-month, six-month put-call skews have remained negative in the past week, implying stronger demand for long-term calls.Not everyone is convinced an Ether ETF will hit the market just yet. Sui Chung, CEO of CF Benchmarks, a crypto indexes provider, said he anticipates that the product may arrive sometime in mid-2022, pointing out that it will require a stronger liquidity and open interest in the underlying ether futures market before the launch.As of Tuesday, the amount of money locked in the ether futures contracts on derivatives exchanges totaled at $10.4 billion. For comparison, the dollar value of bitcoin futures’ open interest was nearly $25 billion on the same day.