This repository contains the data and MATLAB code used to reproduce the analyses and figures associated with the manuscript “Niche Overlap Is Not Enough: Same Overlap, Contrasting Fluctuations.” The archive includes MATLAB scripts for stochastic consumer-resource simulations, analytical correlation calculations, figure generation, and empirical reanalysis of microbial abundance data. The uploaded files include simulation code, empirical abundance matrices, yield and depletion matrices, and a README file describing the repository contents and reproduction steps. Empirical data are derived from the dataset of Crocker et al., available at OSF DOI: 10.17605/OSF.IO/J8S2V. Processed subsets relevant to the yield–depletion mismatch analysis are included here for reproducibility. The code supports the analyses reported in the manuscript, including the relationship between yield–depletion mismatch, niche overlap, growth-rate correlations, and abundance correlations in stochastic consumer-resource dynamics.