Have you heard of a stock correlation screener? Input: Stock ticker Output: Highest correlated stocks over some period
https://www.portfoliovisualizer.com/asset-correlations https://www.portfoliovisualizer.com/asset-class-correlations
There was this market-topology.net website that shows related stocks in a tree-node form. It no longer exists but I plan to make something similar when I have time, will likely share it in GitHub page.