How to build an investment portfolio from scratch

Building an investment portfolio doesn't require being a market expert or having a lot of money. It requires a clear plan, simple products and the discipline not to react to every market headline. This guide takes you from zero to having an operational portfolio adapted to your profile.

  • A portfolio with 1–3 global ETFs historically beats most actively managed portfolios
  • Diversification reduces risk without necessarily reducing expected return
  • The split between equities and bonds should be adjusted to your time horizon, not your mood
  • Annual rebalancing keeps risk controlled and forces you to buy low and sell high
  • The biggest mistake isn't choosing the wrong assets — it's panic-selling during falls

Before you start: define your profile

Before choosing any asset, you need to answer three questions:

  1. When will you need this money? If it's in less than 3 years, the stock market isn't the right place — use a money market fund or deposit. If it's in more than 10 years, you can absorb more short-term volatility.
  1. How would you react if your portfolio fell 30%? If you'd panic and sell, your profile is conservative even if you think it isn't. If you'd hold and take the opportunity to buy more, you can take on more risk.
  1. What is this money for? Retirement (long horizon), house purchase (medium horizon) or financial independence (variable horizon) all have different strategies.

The basic building blocks of a portfolio

A diversified portfolio combines assets with different behaviours:

Equities (stocks/ETFs): higher expected return over the long term, higher volatility. The growth engine.

Fixed income (bonds/bond ETFs): lower return, lower volatility. The buffer.

Cash / money market funds: immediate liquidity, low but positive return. For the emergency fund and opportunities.

Real estate (REITs or direct property): additional diversification, moderate correlation with equities.

You don't need all these blocks. For most retail investors, equities plus a small fixed income allocation is sufficient.

Allocation by profile

Aggressive profile (horizon >15 years, high tolerance): 90–100% equities (global ETF). Example: 100% VWCE or IWDA.

Moderate profile (horizon 8–15 years, medium tolerance): 70–80% equities + 20–30% bonds. Example: 80% IWDA + 20% AGGH.

Conservative profile (horizon <8 years or low tolerance): 40–60% equities + 40–60% bonds. Example: 50% IWDA + 50% AGGH.

Approximate rule: your equities percentage can be 110 minus your age. At 30 → 80% equities. At 50 → 60% equities. It's a guide, not a law.

Rebalancing: why and how

Imagine you start with 80% equities and 20% bonds. After a good stock market year, equities rise and your portfolio is now 88% equities and 12% bonds — more risk than you planned.

Rebalancing means returning to your target allocation. Two ways to do it: sell what has risen and buy what has fallen (triggers taxes if there are gains), or rather than selling, direct your new monthly contributions to the asset that's below its target (more tax-efficient).

Recommended frequency: once a year, or when the deviation exceeds 5% of the target allocation. More frequent adds no value — it just generates more transaction costs.

The simplest portfolio that works

If you want maximum simplicity with proven results, the single-ETF portfolio is perfectly valid:

100% VWCE — you hold ~3,700 companies worldwide, with automatic internal rebalancing by market capitalisation. Zero additional decisions. Fee: 0.22%/year.

If you prefer two ETFs: 80% IWDA + 20% AGGH. Slightly more control, mild conservative tilt.

If you want three ETFs (classic Boglehead portfolio): 60% IWDA + 20% emerging markets (EMIM) + 20% bonds (AGGH).

More complexity doesn't mean better results. The most sophisticated portfolio doesn't systematically beat the global index. The key is consistency: investing every single month without exceptions, for years.

Frequently asked questions

What is a diversified portfolio?

One that spreads money across asset classes, regions and sectors so that no single investment can badly damage the whole.

How many funds do I need?

Two or three broad index funds (global equity plus bonds) can already offer broad diversification.

How often should I rebalance?

Once a year, or when an asset class deviates more than about 5 percentage points from its target.

What percentage in stocks?

It depends on your horizon and risk tolerance. Longer horizons can hold more equities; closer goals need more stability.

Read further

  • A Random Walk Down Wall Street (Burton G. Malkiel). It gives you: Explains with history and data why index investing is the sensible choice for most people.
  • The Algebra of Wealth (Scott Galloway). It gives you: Brings career, stoic discipline and investing into one view, which no other book in the Library covers.