BIS Paper No. 170: Stablecoins Already Facilitating Currency Substitution
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 Salvado…