Diversification as a concentration check
Many “diversified” portfolios are one big ticker in disguise. A diversification calculator asks whether weights cluster too hard in a single asset, sector, or theme. It will not compute true statistical risk, but it will surface the obvious: if one line is most of the pie, your story is not diversification.
What to do with the result
If concentration is high, decide consciously—high conviction is allowed—or rebalance toward broader funds. Pair with risk-vs-return and ROI tools. Not investment advice; private browser math for clearer kitchen-table talks.