Investing in Bitcoin and other digital currencies remains a risky game where the rules could change significantly, but the payoff could be big. 

In response to this dilemma, several leading US financial heavyweights are staying on the sidelines, while an increasing number are proceeding cautiously into the growing world of cryptoassets.

"My own personal advice to people: Stay away from it," JPMorgan Chase Chief Executive Jamie Dimon said recently, before adding, "That does not mean the clients don't want it."

JPMorgan, the biggest US bank by assets, is currently assessing how it can help clients transact in cryptocurrency, Dimon said last month at the bank's annual meeting.

Formerly something of an investment sideshow dominated by computer geeks, cryptocurrencies are sparking greater interest among mainstream investors after a big jump in Bitcoin prices in 2020 and early 2021.

On Thursday, the venerable giant State Street announced the creation of a new digital finance division.

On Wednesday, the head of online trading firm Interactive Brokers vowed to establish online trading of cryptocurrencies on the platform by the end of the summer.

Like its rivals Charles Schwab and Fidelity, Interactive Brokers does not now offer Bitcoin trading on its platform, although it does give clients the option to invest in some assets that include cryptocurrencies or Bitcoin futures.

Investors who want to trade Bitcoin can currently turn to Robinhood or the cryptocurrency specialist Coinbase.

ForUsAll, a platform that manages retirement accounts for small businesses, on Monday announced an agreement with Coinbase that allows clients to invest up to five per cent of their balances in cryptocurrencies.

Investment bank Morgan Stanley in March said it would allow wealthier clients to invest in Bitcoin funds, while Goldman Sachs recently established a team dedicated to trading cryptocurrencies.

The chief executives of Wells Fargo, Citigroup and Bank of America said at a congressional hearing in late May that they are approaching the cryptocurrency landscape with caution.

Fidelity Investments, which established a digital assets division in 2018 to execute cryptocurrency trades for hedge funds and other institutional investors, filed papers with US securities regulators for a Bitcoin exchange traded fund (ETF).

The move could potentially expand cryptocurrency investments to a broader range of individual investors.

 Tougher rules ahead? 

Still, many financial players are reluctant to dive into an investment realm associated with black markets that has sparked interest from US and global regulators.

There is also remarkable volatility, with Bitcoin beginning 2021 at around $30,000 and hitting $63,000 in April before falling back to $34,000 in June.

"Speculators and those suffering from FOMO [the 'fear of missing out'] will surely continue to flock to cryptos in the hopes of achieving huge returns," said Ian Gendler of research firm Value Line.

But Gendler urges clients to avoid cryptocurrency investments, citing the elevated risk and the lack of a tangible asset compared with putting money into commodities or a company. Bitcoin and other digital money is also not backed by governments, he noted.

"Cryptocurrencies are only worth what the next investor is willing to pay," he said.

Still, many in finance do not see cryptocurrency as a transient phenomenon.

"We do believe Bitcoin, and more broadly cryptoassets, are a new and emerging asset class that will likely be here to stay," said Chris Kuiper, vice president at CFRA Research.

CFRA expects "the large banks as well as smaller financial institutions to continue to adopt them, particularly as the infrastructure and legal/regulatory framework continues to be built out", Kuiper added.

The Basel Committee, which coordinates regulation among central banks, this week proposed new rules that would require banks to set aside capital for cryptocurrency investments.

Gary Gensler, the new head of the Securities and Exchange Commission, has also said he wants to bolster protections for cryptocurrency investors, telling CNBC that such investors "don't have full protections that they have in the equity markets or in the commodity futures market."