An underappreciated corner of crypto is shaping US government debt markets. Stablecoins, a type of cryptocurrency designed to retain a stable value, was once seen mainly as digital cash for trading. But stablecoins now hold hundreds of billions of dollars in Treasury bills. And flows into or out of stablecoins can move short-term yields, shift liquidity conditions, and alter Treasuries’ safe-haven role.
For investors, that means a new source of volatility in the world’s most important safe asset, one that links portfolio resilience to crypto-market sentiment.
The Bank for International Settlements (BIS) estimates that inflows into stablecoins reduce 3-month T-bill yields by 2 to 2.5 basis points within 10 days, while outflows lift yields by 6 to 8 basis points in the same time period. In its report, “Stablecoins and safe asset prices,” BIS notes that stablecoins pegged to the US dollar and backed by T-bills increasingly resemble money market funds. After the $5 trillion debt ceiling hike increased T-bill issuance, stablecoins’ contribution toward absorbing upsized ($100 billion) weekly 4-week T-bill issuance has underscored cryptocurrencies’ role as funding provider for US federal expenditure, especially when total US public debt outstanding surged $700 billion in the month of July 2025 (Figure 1).
Figure 1.
Source: Treasury Department’s “Debt to the Penny” portal.
When Crypto Sentiment Drives Treasury Liquidity
A paradox emerged as a major fiat haven asset (and funding channel for the US federal government) became closely coupled with instruments active in decentralized finance (DeFi). In “Stablecoins and Crypto Shocks: An Update,” New York Federal Reserve researchers concluded “demand for stablecoins grows along with demand for non-stablecoin crypto assets (as proxied by Bitcoins)” and “the demand for stablecoins appears to be tied to activity levels in the broader crypto ecosystem.”
This suggests that a decline in broader crypto sentiment (e.g. Bitcoin downturn) could correspond to less demand for stablecoins, and outflows from stablecoins to cash could result in collateral shedding. This risk-off to T-bill liquidation feedback loop risks eroding the latter’s haven characteristics.
Furthermore, as of June 30, the largest stablecoin, Tether (USDT), held 20% of its reserves in corporate bonds, precious metals, Bitcoins, other investments, and secured loans. These less-liquid assets would be less capable of meeting cash demands during a funding crunch, and this hints at “dash for cash” via T-bill sales during adverse market shocks. A Brookings analysis highlighted this dynamic during the March 2020 volatility event as institutions sold Treasuries, the most liquid assets available on institutional balance sheets, to meet funding needs at the height of the equity rout.
Th New York Fed highlighted the dominance of Tether and USDC in the stablecoin market, and both are large T-bill holders (Figure 2).
Figure 2.
A Fair-Weather Funding Channel with Investor Risks
The amplification of T-bill flows by stablecoins could act as a double-edged sword in shaping US market conditions. During “fair-weather” periods, healthy inflows into the crypto markets (and growth in stablecoins) would boost demands for T-bills to help offset the trend rise in US short-term debt sales.
Conversely, market instability and broader liquidity drought (that reduce risk appetite in cryptocurrency markets) could reduce stablecoins’ footprint in the Treasury market, thus leaving a greater portion of issuance to be absorbed by fixed income investors. This would likely come at a time of rising government benefits disbursement and lower tax receipt.
Finally, CME analysis noted growing institutional acceptance of cryptocurrencies and their integration alongside traditional investments, which would likely contribute to higher equity and Bitcoin correlation. Combined, higher correlation between traditional risk assets and crypto markets, co-movements between digital asset sentiment and stablecoin market cap, and the casual relationship between stablecoin market cap and demand for T-bills suggest higher US fiscal and sovereign bond market sensitivity to cryptocurrency volatility.
Conclusion: Fragility Behind the Stablecoin–Treasury Link
In conclusion, higher T-bill demand induced by broader allocations into cryptocurrencies represents greater fragility in the short-term dollar funding market. Stablecoins’ “fair-weather” debt purchases offer only a temporary reprieve for fiscal authorities, offsetting issuance pressures but not permanently absorbing them.
For portfolios, the risk is hidden but real: a virtuous cycle in calm markets can turn vicious in stressed conditions. As volatility rises, stablecoin outflows and collateral sales could erode Treasuries’ safe-haven role, leaving investors more exposed just when protection is needed most. Investors may need to stress-test their reliance on Treasuries as a safe-haven, and prepare for funding dynamics increasingly shaped by crypto-market sentiment.
