The Bank for International Settlements has published a working paper analysing how flows into and out of USD-backed stablecoins affect US Treasury yields, using daily data from January 2021 to March 2025. The paper estimates that stablecoin inflows compress 3-month Treasury bill yields by around 2 to 2.5 basis points within 10 days, with limited evidence of spillovers to longer maturities. Using instrumented local projection regressions, the authors find that a USD 3.5 billion five-day inflow (around two standard deviations) lowers 3-month yields by about 2 to 2.5 basis points, while outflows raise yields by two to three times as much. Decomposition by issuer attributes roughly 70% of the estimated yield effect to USDT (Tether) and about 19% to USDC (Circle), broadly consistent with their relative size and disclosed reserve composition. The paper highlights implications for monetary policy transmission, stablecoin reserve transparency, and financial stability risks associated with potential run-driven fire sales.