Stablecoins are the shiny new object on Wall Street. Once restricted to the niche world of crypto trading, stablecoins entered the mainstream of U.S. finance as Congress debated—and ultimately passed in July—a bill to legitimize them and expand their use. That has spurred a hype cycle as banks and Fortune 500 companies rush to explore the technology.
Stablecoins, which are typically pegged to the U.S. dollar and backed 1:1 to a pool of reserves, have been around for a decade. But their soaring popularity has brought mounting questions over how their growth could impact the broader economy. Financial experts and government officials alike are grappling with the implications of giant stablecoin issuers Tether and Circle becoming some of the largest holders of U.S. Treasuries, rivaling countries like South Korea and Saudi Arabia.
While crypto proponents argue that stablecoins will help extend dollar dominance across the globe, critics warn that they could lead to financial instability in the banking sector, even as they remain a tiny portion of overall markets.
A new financial plumbing
To get a sense of stablecoins’ growing popularity, it’s worth noting that their transaction volume surpassed Visa in early 2024. While much of this activity occured in the context of crypto trading, it supported advocates’ case that stablecoins’ low fees and near-instantaneous speeds make them a superior vehicle to older technology like SWIFT, especially when it comes to moving money across borders. That argument has broken out of the crypto industry, with the fintech giant Stripe acquiring the stablecoin startup Bridge last year for $1.1 billion.
In order to ensure a stablecoin maintains on par with a dollar, most issuers purchase large quantities of Treasury bills to serve as the bulk of their reserves. Tether, the largest stablecoin issuer, holds over $100 billion in T-bills, according to its latest attestation, which ranks it ahead of countries such as the United Arab Emirates and Germany. According to a July report from Apollo, the stablecoin industry as a whole is now the 18th largest external holder of Treasuries.
To be fair, this is still a blip compared to the U.S. money market fund sector, which stands at around $7 trillion, mostly comprised of Treasuries. But, especially with July’s passage of the Genius Act, stablecoins are only likely to grow, with Apollo estimating that the sector could reach $2 trillion by 2028. The market cap of USDC, the second-largest stablecoin, has grown 90% over the past year to $65 billion. Its parent company, Circle, went public in June, delivering the largest two-day IPO pop in decades.
At a time when longtime holders of U.S. Treasuries, including China and Japan, are signaling they will move away from the asset class, the emergence of stablecoin issuers as a new buyer of T-bills could serve as an escape valve for the U.S. government. “Having stablecoin issuers always be there is a massive boost in terms of giving confidence to the Treasury [Department] about where to place debt,” said Yesha Yadav, a professor at Vanderbilt Law School who wrote a recent paper on the relationship between stablecoins and the U.S. Treasury market.
Crypto proponents go even further, arguing that the benefits could ripple across the U.S. economy and beyond. They say the growth of stablecoins could consolidate the dollar’s dominance as a method of payment for foreign payments, similar to the “eurodollar” (a term that signals dollar deposits held outside the U.S.), and could help the U.S. government enforce sanctions abroad. David Sacks, the White House’s AI and crypto czar, went so far as to argue that new demand for U.S. Treasuries from stablecoin companies could lower long-term interest rates.
Others—including Yadav and State Street’s global head of cash and digital asset, Kim Hochfeld—are more skeptical, especially given the nascent sector’s footprint. “There’s a lot of hype, and the numbers are still tiny compared to what we see in normal TradFi,” Hochfeld told Fortune. “While I don’t deny this is the start of a big trend, the numbers are still not enough to make us either super excited or super nervous.”
Some critics, including bank lobbying groups, have warned that stablecoins could siphon money away from bank deposits as customers shift holdings to stablecoins. Because deposits serve as necessary liquidity for lending, they argue, stablecoins could threaten the credit system. One stablecoin executive, who spoke with Fortune on the condition of anonymity to discuss sensitive industry relationships, described the argument as “politically expedient,” pointing out that bank lobbying groups have previously invoked the argument to resist the introduction of now commonplace financial instruments like money market funds.
“There are trillions of dollars in money market funds,” said the executive, “Ultimately, it didn’t affect banks being able to make loans.”
Yadav said that stablecoins’ growth could still lead to unintended outcomes, especially as they hoover up short-term Treasuries, which many Wall Street institutions rely on for risk management and other forms of financial engineering. “What that means for the rest of the financial system as [stablecoins] become gargantuan is anybody’s guess,” she told Fortune.