Correlation matrices of third-order aperture mass measures in the T17 ensemble. Shown are the results for the non-tomographic, equal-scale statistics (top left), the non-tomographic unequal-scale statistics (bottom left), and the tomographic equal-scale statistics (right-hand side). We order the statistics such that θ_i ≤ θ_j ≤ θ_k and Z₁ ≤ Z₂ ≤ Z₃, meaning that each of the “small” 35² squares in the covariance matrix on the right-hand side corresponds to the cross-covariance of the statistics for fixed tomographic redshift bin combinations.