THEME 08 · CORE

Building a portfolio

Twenty holdings in one sector isn't diversified — it's one bet, twenty ways. How to see the shape of what you own. — 10 lessons · 28 terms · 2 playbooks

The lessons

  1. 8.1

    Don't keep all your acorns in one tree

    How spread out is spread out enough — and how to spot a lopsided portfolio.

  2. 8.2

    Thirty holdings can still be one bet

    Counting holdings measures the wrong thing.

  3. 8.3

    What correlation looks like on a chart

    Two lines that move together, and what that costs you.

  4. 8.4

    What concentration risk actually means

    The winner that grew fastest is now your biggest risk.

  5. 8.5

    Home bias: why UK investors hold so much UK

    Familiarity, dividends, and an accidental currency bet.

  6. 8.6

    Asset allocation: the decision that does most of the work

    The split between kinds of things you own, before which things you own.

  7. 8.7

    Position sizing without a formula

    Why "how much" is a question about consequences, not maths.

  8. 8.8

    Rebalancing explained without the jargon

    Trimming what grew, topping up what didn't, back toward your targets.

  9. 8.9

    Lump sum vs regular contributions

    What each approach does mechanically. Described, not recommended.

  10. 8.10

    What the portfolio health score is measuring

    The four inputs behind the number, and what each one can't see.

Educational content only. It is not personal financial advice.