BIS Paper No. 170: Stablecoins Already Facilitating Currency Substitution
The Bank for International Settlements formally concludes that dollar-pegged stablecoins are actively substituting domestic currencies in vulnerable economies, with a $310 billion market now posing systemic risks to EMDE monetary sovereignty and quietly financing US sovereign debt.
The Bank for International Settlements has formally entered the stablecoin debate not as an observer but as an alarm-raiser. BIS Papers No. 170, published May 5, 2026, and authored by Iñaki Aldasoro, Jon Frost, and Hiro Ito, concludes that stablecoins "are already facilitating a form of digital currency substitution in specific contexts" [1]. The finding, coming from the central bank for central banks, removes any remaining ambiguity about whether this phenomenon is speculative or operational.
Scale and Structure of the Market
The report documents a market that has grown to exceed $300 billion in capitalisation, with cross-border transaction volumes surpassing $400 billion as of 2024 [1]. The currency composition is extreme: dollar-denominated stablecoins account for 98.1% of total market value, even as the dollar represents only 64.4% of all stablecoin issuances by number. That gap between count and value confirms the structural dominance of Tether (USDT) and USD Coin (USDC), the two instruments driving real-economy adoption.
Reserve backing compounds the dollar dimension further. Stablecoin issuers hold their reserves predominantly in short-dated US Treasury bills, creating what the BIS describes as a direct channel feeding US sovereign debt demand. The SUERF Policy Brief by Danielsson and Macrae frames the mechanism in historical terms: stablecoins function as the on-chain analogue of the eurodollar system, private dollar liabilities circulating beyond the US financial system while being anchored to it [4]. Every dollar of stablecoin outstanding effectively creates demand for Treasuries, delivering a fiscal subsidy to Washington that echoes the "exorbitant privilege" first named by French Finance Minister Valéry Giscard d'Estaing in the 1960s.
The stablecoin universe has now surpassed offshore Swiss franc liabilities (approximately $1.5 trillion in total offshore USD liabilities sit at around $14 trillion), a threshold the BIS treats as meaningful in assessing systemic relevance [1].
Three Scenarios
The paper structures its risk analysis around three forward scenarios, each carrying distinct policy implications:
Scenario — Core Dynamics — EMDE Implications
1. Niche Adoption — Stablecoins remain confined to crypto trading, DeFi, and targeted remittance corridors — Limited sovereignty erosion; policy autonomy largely preserved
2. Digital Dollarisation — Rapid USD-stablecoin uptake in domestic and cross-border payments; banks offer on/off-ramps; pricing shifts to dollar — Acute monetary sovereignty loss; capital controls bypassed; FX volatility and deposit flight risk
3. Domestic Stablecoin Integration — EMDEs license local-currency stablecoins interoperable with payment systems and CBDCs — Efficiency gains and financial inclusion; policy autonomy preserved; requires high regulatory capacity
The BIS characterises near-term niche adoption as most plausible, while treating the digital dollarisation scenario as a genuine, non-trivial risk. The domestic integration pathway, though theoretically attractive, is described as aspirational, requiring regulatory infrastructure that most vulnerable EMDEs do not yet possess [1].
EMDE Vulnerability and the Sovereignty Erosion Mechanism
Cross-border stablecoin flows have grown substantially since 2022. The BIS finds that Asia-Pacific leads in absolute transaction volumes, but Africa, the Middle East, and Latin America show higher stablecoin activity relative to GDP, precisely the regions where domestic currency confidence is weakest [1]. The SUERF analysis quantifies this: stablecoin purchases in Turkey reached an estimated 4.3% of GDP in 2023-24, with comparable patterns in Argentina, Nigeria, Lebanon, and Cambodia [4].
"Rapid adoption of foreign currency stablecoins risks eroding monetary sovereignty... In economies with weak monetary frameworks or high inflation, foreign currency stablecoins can serve as a de facto store of value and payment instrument." - BIS Papers No. 170 [1]
The mechanism follows a sequenced path: store of value adoption precedes medium-of-exchange adoption, which precedes unit-of-account displacement. Statistical work cited in the paper finds that a 1% increase in stablecoin flows produces measurable parity deviations, cumulative domestic currency depreciation, and covered interest parity violations [1]. These are empirically documented transmission effects. The central geopolitical irony: countries most vulnerable to stablecoin-driven dollarisation are also those least equipped to respond [2].
Sanctions, Dollar Dominance, and the US Regulatory Posture
The World Economic Forum flagged this dynamic in April 2026, noting that stablecoins now sit at the intersection of technology, money, and geopolitical power, with the dollar's digital extension creating asymmetric dependencies [3]. The analysis connects directly to US legislative strategy: the CLARITY Act and the previously enacted GENIUS Act both embed reserve requirements in short-dated Treasuries, which simultaneously regulates the market and structurally deepens stablecoin-to-Treasury demand linkages. One stablecoin-based platform documented by the WEF processes over $45 billion in annualised payment volume, with 98% of transactions settling in under 60 minutes [3].
For sanctions architects, the BIS paper carries a dual implication. Dollar stablecoins extend US financial infrastructure reach into jurisdictions formally outside it, but that same reach creates vulnerability: US sanctions already drive some sovereigns to seek alternative payment rails, and stablecoin dependency creates leverage that can be applied or resisted [4]. Brazil's Banco Central demonstrated one response model with BCB Resolution 561, which brought cross-border stablecoin flows inside the domestic regulatory perimeter rather than excluding them.
The transparency dimension remains unresolved. The BIS notes that Tether, the largest stablecoin issuer by market value and a Salvadoran-domiciled entity, has not issued audited financial statements [1]. FSB implementation of international stablecoin standards remains uneven across five assessed stages. MiCA in the EU and the GENIUS Act in the US represent the most advanced frameworks, but neither resolves what happens when a peg breaks without a central bank backstop.
Stablecoin Reserve Composition and US Debt Demand
Reserve Component — Role in Stablecoin Backing — US Sovereign Debt Impact
Short-dated US Treasury bills — Primary reserve asset for major issuers — Direct demand channel; reduces marginal yield
Treasury-backed money market funds — Secondary holdings — Indirect Treasury demand
Commercial bank deposits — Liquidity buffer — Limited sovereign debt linkage
Other cash equivalents — Residual — Minimal direct impact
At current market size, stablecoin-driven Treasury demand is modest relative to the roughly $28 trillion outstanding US debt stock. The BIS frames the trajectory as more significant than the current stock, particularly if the digital dollarisation scenario unfolds in EMDEs with growing stablecoin exposure.
Policy Conclusions
The BIS recommends that EMDEs strengthen macroeconomic frameworks, accelerate domestic fast-payment infrastructure and CBDC development, and consider targeted restrictions on foreign-currency stablecoin use while deploying on-chain analytics for monitoring [1]. At the international level, the paper calls for coordinated reserve transparency standards, resolution frameworks, and consistent FSB implementation.
The conclusion carries weight because of its source: this is not an academic warning but the BIS view, delivered in a numbered working paper series that shapes supervisory consensus across its 63 member central banks. The question of whether stablecoins are already monetary substitutes has been answered. Whether policymakers can respond before digital financial subordination becomes structurally embedded has not.
References
[1] Aldasoro, Frost, Ito, "The impact of stablecoins on the international monetary and financial system," BIS Papers No. 170, May 5, 2026. https://www.bis.org/publ/bppdf/bispap170.pdf
[2] Central Banking Newsdesk, "Geopolitics complicates stablecoin adoption, BIS paper finds," Central Banking, May 7, 2026. https://www.centralbanking.com/fintech/7975858/geopolitics-complicates-stablecoin-adoption-bis-paper-finds
[3] World Economic Forum, "Why stablecoins are becoming a geopolitical issue," April 2, 2026. https://www.weforum.org/stories/2026/04/why-stablecoins-are-becoming-a-geopolitical-issue/
[4] Danielsson and Macrae, "Stablecoins and dollar hegemony," SUERF Policy Brief No. 1440, May 2026. https://www.suerf.org/wp-content/uploads/2026/05/SUERF-Policy-Brief-1440_Danielsson-Macrae.pdf