Concentration

Measure how diversified your portfolio really is. Firma computes the Herfindahl-Hirschman Index (HHI) across four dimensions: ticker, currency, sector, and country.

What is HHI?

The HHI is the sum of squared market-share fractions, scaled to 0-10,000. A portfolio with a single holding scores 10,000, which is maximum concentration. Equal weights across many holdings approach 0.

< 1500Low: well diversified

1500 – 2500Moderate: some concentration

2500 – 5000High: consider rebalancing

> 5000Very high: heavily concentrated

firma show concentration

Shows the HHI score and severity for each dimension, along with the top contributors by market value weight.

$firma show concentration

DIMENSION	HHI	SEVERITY	TOP HOLDINGS

Ticker	5841	very high	TSLA 74%, NVDA 16%, AAPL 6%, MSFT 4%
Currency	10000	very high	USD 100%
Sector	5884	very high	Automobiles 74%, Semiconductors 16%, Technology 10%
Country	10000	very high	US 100%

<1500 low · 1500–2500 moderate · 2500–5000 high · >5000 very high

  Rebalance hint  →  sell ≈428 TSLA @ $350.40  ·  TSLA: 74% → 50%  ·  HHI → <2500

Sector and country data comes from Finnhub via firma sync. Tickers without price data are excluded from the calculation.

Reading the Rebalance Hint

When ticker HHI exceeds 2500, firma appends a one-line rebalance suggestion below the table. It finds the minimum amount to sell from the most concentrated position to bring ticker HHI below 2500.

sell ≈428 TSLA @ $350.40How many shares to sell and around what price. The share count is estimated from the last synced price, so the actual execution price will differ.

TSLA: 74% → 50%Your dominant ticker's portfolio weight before and after the suggested sale.

HHI → <2500The target after the sale. The boundary between "high" and "moderate" concentration.

This is a mechanical heuristic, not financial advice. The hint only considers ticker-level HHI and targets a single threshold. Whether to act on it depends on your tax situation, conviction in the position, and the transaction costs involved.

Options

firma show concentrationHHI across all four dimensions

firma show concentration --jsonMachine-readable output with top slices per dimension

With Claude

Claude Desktop · firma MCP connected

You

Am I too concentrated in any one stock?

Claude

Yes. Ticker HHI is 5,841 (very high). TSLA is 74% of the portfolio. A 10% move swings your total value by roughly $15,000. Currency and country both score 10,000 because the portfolio is entirely USD and entirely US. Sector concentration mirrors ticker concentration, with Automobiles at 74%.