What if the "stable" in stablecoins is a ticking time bomb for the global economy? The European Central Bank is sounding the alarm, revealing how these digital assets could destabilize traditional banking. With a market value exceeding $280 billion, stablecoins are involved in a staggering 80% of all crypto trades, and the largest issuers hold reserves comparable to the top 20 money market funds. A sudden investor "run" could force a fire sale of their U.S. Treasury holdings, creating shockwaves that rattle global markets. This creates a direct threat of contagion, where a crypto crisis could spill over and trigger a systemic financial meltdown. In practice, this means a popular tool for crypto trading could suddenly siphon essential deposits from Eurozone banks, creating a modern, digital-age bank run.