The statement that the European Central Bank (ECB) issued a warning that stablecoin growth could weaken the effectiveness of monetary policy is strongly supported by the ECB’s own official communications and research publications. Top-level speeches and publications by the ECB President and staff explicitly address concerns that widespread use of stablecoins could alter monetary transmission channels, reduce the central bank’s control over monetary conditions, and challenge the dominance of the euro as the unit of account. The ECB’s speeches to the European Parliament and policy blogs directly articulate potential risks of stablecoins to monetary sovereignty and policy effectiveness. Working papers and research further examine these risks within the framework of monetary policy transmission. These materials are authoritative, internally consistent, and directly sourced from ECB officials and economists, leaving little ambiguity that such a warning has indeed been issued. There is no credible evidence in the reviewed sources contradicting that the ECB has expressed this concern, hence the statement is highly likely to be true.