Fermion Mass Ratios as Hypercharge Powers of the Cabibbo Angle

We observe that all nine inter-generation charged fermion mass ratios at the GUT scale can be expressed as powers of the Cabibbo angle λ = sin θC = 0. 2253, where the power is determined by the hypercharge |YR| of the right-handed fermion and the color multiplicity Nc of the sector. Two formulas emerge: for sectors with symmetric Yukawa matrices (up-type quarks in SU (5) ), the inter-generation mass ratio is λ^ (2Nc|YR|) ; for sectors with general Yukawa matrices (down-type quarks), the ratio is λ^ (2+2|YR|), with Georgi–Jarlskog corrections relating leptons to the down sector. Using the 2-loop Standard Model running Yukawa couplings of Antusch, Hinze, and Saad (2025) at μ = 10¹6 GeV (PDG 2024 input, mH = 125 GeV), all nine ratios are reproduced within 27%, with the best-fit λ = 0. 229 lying within 1. 6% of sin θC. A preliminary statistical assessment suggests p < 10^−5, subject to a rigorous Monte Carlo study with a well-defined null hypothesis. The Cabibbo angle's organizing role extends beyond mass ratios. Two additional numerical observations are reported: the Jarlskog invariant J ≈ λ⁷ to 4. 4% precision, and the CKM CP-violating phase δ₁₃ ≈ π/2 − 2θC to 2. 4% precision (within 1σ of the measured value). These suggest that λ organizes both the mass hierarchy and CP violation in the quark sector. The observation that the Standard Model hypercharge Y plays the role conventionally assigned to an independent Froggatt–Nielsen charge appears to isolate an unusually minimal Y-only subcase of prior anomalous U (1) models, which use Y as one component of a multi-parameter charge assignment rather than as the sole flavor charge.