The Spanish Central Bank has issued a warning in its 2026 Spring Financial Stability Report about the potential risks associated with the widespread adoption of stablecoins. The bank highlighted concerns that stablecoins could exacerbate currency substitution, increase cross-border financial flows, and amplify the cross-border transmission of shocks from U.S. monetary policy and other jurisdictions. The report noted that the global stablecoin market capitalization has surpassed $320 billion, with dollar-denominated stablecoins accounting for 98% to 99% of the market, while euro-denominated stablecoins represent only about 0.2%. The Spanish Central Bank also expressed concerns about the regulatory fragmentation and crisis management coordination risks posed by stablecoins like USDC and USDT, which are issued across multiple jurisdictions. These issues could complicate regulatory oversight and response efforts in the event of financial instability.