Portfolio Builder — Risk and Diversification Feedback

Pick the companies and index funds you would actually want to own, set how much goes into each, and see what your mix is really betting on. No real money is involved and nothing you build here is advice.

What you get back

• A concentration score out of 100, with a plain-English risk band
• A breakdown of how much of your money sits in each sector
• Warnings when one company or one sector dominates the portfolio
• An "Explain my portfolio" button that reads your mix back to you in teen-friendly language

Why diversification matters

If one company is 60% of your portfolio, one bad year for that company is a bad year for you. Spreading money across companies, sectors and broad index funds means no single piece of bad luck decides your result. You can also import the holdings from your latest simulator run and see how diversified your practice trading actually was.