We ran the pairwise correlations between every stock in the S&P 500 and every other stock in the index (249,500 computations!) from the 2007-8 financial crisis until now.

A model of quadratic exponential form is parametrized in terms of marginal means and pairwise correlations for the regression analysis of correlated binary data. Pseudo-maximum likelihood methods ...

R. L. Prentice, Binary Regression Using an Extended Beta-Binomial Distribution, With Discussion of Correlation Induced by Covariate Measurement Errors, Journal of the American Statistical Association, ...