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Not investment advice. Educational reading. See Disclaimer.
L.28 · BEGINNER · 3 MIN

Diversification: Don't Put All Eggs in One Basket

The first diversification decision is not which stocks to own -- it is how you split your money across asset classes (stocks, bonds, cash), then across the globe, and finally across vehicles. Picking sectors comes last, because a single total-market index fund already does it for you.

Quiz · 5 questions ↓
§ 01
Asset classBest for money you need...How much it can swing in a bad year
Stocks (e.g., VTI)10+ years from nowDown 20-30% (sometimes more)
Bonds (e.g., BND)3-10 years from nowUsually within about 5-10%
Cash / T-bills (e.g., BIL)Within 1-2 yearsBarely moves
§ 02
RegionRoughly its share of the world stock marketOne fund that covers it
United StatesAbout 60%VTI
Developed markets outside the US (Europe, Japan)About 30%VXUS
Emerging markets (China, India, Brazil...)About 10%VXUS
§ 03
VehicleRole in a beginner portfolioExample
Total-market index fund / ETFThe core -- one fund holds thousands of companiesVTI, VXUS, BND
Target-date fundAll-in-one; picks the mix and rebalances for youVanguard Target Retirement
Individual stocksOptional 'satellite' -- keep it smallAny single company
§ 04

A single total-market fund like VTI already holds every sector in proportion, so you get sector diversification for free. The risks actually worth managing are holding too little in bonds for your time horizon, too little outside the US, and too much in any one stock. (Long-run asset-class behavior: Ibbotson SBBI 1926-2023; global weights track the MSCI All-Country World Index.)

§ 05
Open the **Portfolio** view and look at how your money is split -- across asset classes first (stocks vs bonds vs cash), then across regions, then sectors.
§ 06
You're 100% in stock index funds, and you'll need a third of the money for a house in 2 years. What's the main risk?
§ 07

Diversification is often called 'the only free lunch in investing' -- it lowers risk without necessarily lowering expected return. More precisely, it reduces the risk specific to one company or sector (idiosyncratic risk), not the risk of the whole market falling (systematic risk). You still bear that market risk, and being paid to bear it is exactly why stocks return more than cash over time.

§ 08

If you do buy individual stocks, spreading them across sectors still matters -- a portfolio that is 80% technology (Apple, Microsoft, Nvidia) lives and dies with one sector. But for most beginners this is a second-order concern: a total-market fund already spreads you across all 11 S&P 500 sectors automatically, from technology and healthcare to financials, consumer staples, and energy.

Five questions · AI feedback

Sit with the ideas.

You're saving for a house you plan to buy in about 2 years. Where should most of that money sit?

Why:
Try this in paper trading

Build a 3-ETF starter portfolio

Allocate $25,000 of your paper cash across three ETFs: a broad-market index (e.g., VTI or SPY), an international fund (e.g., VXUS), and a bond fund (e.g., BND or AGG). Pick the weights you'd actually hold for the next decade.

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Practice mode — simulated trades, not investment advice.

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