Correlation Matrix R

Fills a square correlation matrix for a list of tickers, giving every pair a coefficient over the lookback you set, with company names and last prices labelling the rows and columns. Shading makes clusters of highly correlated holdings visible at a glance, which is the usual first check before assuming a portfolio is diversified. Add or remove symbols and the grid expands with the same formula pattern, recalculating whenever the add-in refreshes the data.