Not long after the debut of BlackRock’s bitcoin exchange-traded fund (ETF), the asset manager’s CEO Larry Fink effectively began the marketing drive for a second spot ETF product with the underlying cryptocurrency of Ethereum, citing the value of that blockchain’s transformational utility.

The Wall Street machine needs to be fed and pushing more crypto ETFs is an obvious choice, especially given the attention the bitcoin (BTC) product has garnered. This essentially means thousands of salespeople having meetings, showing a new product, saying what it does, and seeing if people want to buy it.

But selling an ether (ETH) ETF could present an interesting conundrum to issuers. Investors may have just bought a bitcoin ETF, so the practical need to spice up portfolios is already being satisfied. Why would they need another crypto diversification tool?

It’s something Sui Chung, the CEO of CF Benchmarks, an index provider for digital assets and partner firm on the BlackRock iShares bitcoin ETF (IBIT), has been thinking about, especially having recently published a cheat sheet explaining the benefits of a bitcoin-backed security to investors.

Defining bitcoin technology and its potential application to finance is part of the explainer, but Chung believes that’s secondary to the bitcoin ETF’s investment role: a small allocation diversifies a portfolio and boosts the overall risk-adjusted return.

"The primary thing is how bitcoin behaves and its price history," Chung said in an interview. "When you put bitcoin inside a portfolio with stocks, bonds and cash, it’s just the most potent diversifier in the history of investing. You put a little bit in and the Sharpe ratio doubles."

It becomes really interesting as to how a mainstream financial institution– be it BlackRock, Franklin Templeton, Fidelity etc. – markets an ETH ETF to the typical TradFi investor, Chung said. "Because you’ve already sold bitcoin by going down the diversification route; someone’s already stuck 1.5% or 2% of bitcoin into their portfolio.”

In a sense, BlackRock chief Fink has already started diving into the complex world of Ethereum by mentioning tokenization, a much vaunted concept among TradFi firms these days and something most ETF issuers likely believe in wholeheartedly. But such an educational foray should also explain smart contracts and decentralized finance (DeFi), Chung said, not to mention the can of worms that is blockchain staking and the SEC’s opinion of that.

Of course, a key differentiator between Bitcoin and Ethereum is how the latter moved away from the energy-sapping proof-of-work security system to a greener validator model.

"I don’t think ESG [environmental, social and governance] is how it’s going to be marketed,” Chung said. “Do you really want to go there given all the controversy around ESG investing today already? Probably not."

BlackRock declined to comment.