Megan Greene, an external member of the Bank of England's Monetary Policy Committee, made the prediction at a central banking conference in Dubrovnik, Croatia, on May 31. Speaking about the three competing forms of programmable digital money, Greene said the contest is between central bank digital currencies (CBDCs), stablecoins, and tokenised deposits. Stablecoins are privately issued digital tokens pegged to fiat currencies like the US dollar. Tokenised deposits are digital versions of standard commercial bank account balances, running on distributed ledgers but governed by existing banking regulation. CBDCs are digital currencies issued directly by central banks. She cast each technology in an animal metaphor, assigning CBDCs the role of the tortoise, stablecoins the hare, and tokenised deposits the rhino.

"I like to think of it as a massive race between the tortoise, the hare and the rhino," Greene said. "If I had to put money in one, it would be the rhino, tokenised deposits." She added: "I think tokenised deposits are probably going to take over from stablecoins and five years from now, I suspect we might wonder why we were talking about stablecoins."

Not everyone at the same event agreed. Christopher Waller, a governor at the US Federal Reserve, pushed back directly. "I've always just looked at stablecoins as a payment instrument; there's nothing evil about it, nothing dangerous about it," Waller said. "They are just bringing competition into the payments world."

Greene's argument rests on structural advantages that tokenised deposits carry over stablecoins. Unlike stablecoins, bank deposits are covered by deposit insurance schemes and can access central bank liquidity backstops during periods of stress. The 2023 USDC depeg, when Circle's stablecoin briefly lost its dollar parity after holding reserves at the collapsed Silicon Valley Bank, remains a frequently cited example of that vulnerability. Academic analysis cited by Bank of England consultation materials also identifies tokenised deposits as carrying the existing customer relationships and compliance infrastructure of regulated commercial banks, which makes them more legible to regulators across major markets.

Analysis published in the Oxford Capital Markets Law Journal finds that the structural case for bank-backed digital money is likely to prove decisive over time, a position that is gaining ground in policy circles. ECB President Christine Lagarde made a parallel argument earlier this month, warning that dollar-denominated stablecoins are not an efficient way to build the international appeal of the euro, and announcing European infrastructure projects to fill that gap, including the Pontes wholesale settlement project and the Appia tokenised ecosystem, which is targeted for 2028. China pivoted its state digital currency programme at the start of 2026 away from retail CBDCs toward interest-bearing tokenised deposits issued by commercial banks, a real-world move that tracks Greene's thesis.

The problem is that the preconditions for tokenised deposits to work broadly: widespread commercial banking access, trusted bank infrastructure, and permissioned settlement technology, do not exist uniformly across the regions where stablecoins are growing fastest.

Africa provides the sharpest illustration of that gap. According to BVNK's 2026 Stablecoin Utility Report, 79 percent of crypto-active users in Africa hold stablecoins, the highest share of any region in the world, compared with roughly 60 percent in other emerging regions and approximately 45 percent in high-income markets. Sub-Saharan Africa recorded more than $205 billion in on-chain transaction value between July 2024 and June 2025, a 52 percent year-on-year increase, with stablecoins accounting for 43 percent of that activity. One reason is cost: sending money to Sub-Saharan Africa via traditional rails averaged 8.78 percent of transaction value in the first quarter of 2025, against a global average of 6.49 percent. Stablecoin transfers typically run at 0.5 to 1 percent of transaction value. Flutterwave deployed USDC and USDT across 34 African countries via a Polygon partnership in October 2025, in what the company described as the largest stablecoin deployment in Africa. The infrastructure extends well beyond a single provider: Visa has built more than 130 stablecoin-linked card programmes across 40 or more countries, and Yellow Card operates cross-border enterprise stablecoin transactions in more than 20 African countries.

South Asia faces a similar dynamic. India received roughly $135 billion in remittances in 2025, much of it through Gulf corridors where stablecoin infrastructure is, according to analysts, increasingly active. Pakistan's new Virtual Assets Act 2026 explicitly names stablecoin-based remittances and supply chain finance as testing targets in its regulatory sandbox. Bangladesh maintains a strict crypto ban and is integrating India's UPI payment system as an alternative by mid-2026, though tokenised deposits may ultimately prove more palatable to Bangladesh's central bank than decentralised stablecoins once the necessary commercial banking infrastructure is in place.

The scale of stablecoin activity globally reinforces why that transition will not be simple. Stablecoins processed roughly $33 trillion in transaction volume in 2025, a 72 percent increase year on year, with monthly transfer volume reaching approximately $6.10 trillion. Those figures indicate that stablecoins are functioning as active financial infrastructure rather than primarily as speculative holdings.

If Greene's five-year timeline proves correct, the transition will require building out commercial banking infrastructure and regulated deposit-tokenisation rails in markets that currently have neither at the scale required. The Bank of England's Regulated Liability Network and the BIS's Project Agora are among the leading technical efforts working toward standards for that infrastructure, alongside Hong Kong's EnsembleTX, launched in February 2026, and the European Union's Appia tokenised ecosystem, expected in 2028. The BoE's Regulated Liability Network is developing a three-layer settlement architecture, while BIS Project Agora's developer API and SDK specifications remain in progress. In the United Kingdom, the Bank of England launched a separate consultation on regulating systemic stablecoins in November 2025, with supervisory rules expected by the end of 2026, adding a further regulatory layer alongside the Financial Services and Markets Act 2000 (Cryptoassets) Regulations 2026, introduced in February and expected to be finalised in the second half of this year. Together, these efforts will offer an early indicator of how aggressively British regulators intend to constrain the stablecoin market before any credible alternative is ready.

The global stablecoin market stood at approximately $322 billion as of late May 2026, a figure that exceeds the foreign exchange reserves of 95 countries, including the United Kingdom and Canada. That number has grown by roughly $13.5 billion in five months. Whether Greene's rhino gets there in time is a policy question, but for users moving money across borders today, the stablecoin hare is already running.