Mexico's central bank raised fresh concerns about stablecoins in their latest assessment, highlighting a trio of structural vulnerabilities that could threaten financial stability. The primary concern centers on stablecoins' dependency on short-term US Treasury holdings—a concentration risk that becomes acute during market stress. Beyond that, the heavy centralization of stablecoin issuance among a handful of major players creates systemic exposure. Equally problematic is the current patchwork of global regulations, which allows stablecoin providers to exploit regulatory arbitrage across jurisdictions. These findings reflect a broader pattern among central banks worldwide reassessing how digital currencies should be governed. As more institutions enter the stablecoin space, Mexico's warning underscores why coordinated regulatory frameworks matter for protecting both domestic and international financial systems.