Concept
How diversification works
"Don't put all your eggs in one basket" is where most explanations stop. The useful version is more specific: diversification does not raise your average return, it changes how bad your worst year is — and that changes whether you are still invested when the recovery arrives.
Written by the Rise to Riches editorial team · Last reviewed
Two kinds of risk
Owning one company exposes you to two separate things. The first is that company's own fate: a failed product, a bad quarter, an accounting scandal. The second is the market's fate: a recession hits everything at once.
Diversification eliminates the first kind almost entirely and barely touches the second. Hold thirty companies and one going to zero costs you a few percent instead of everything. But if the whole market falls 40%, thirty companies fall with it. This is why spreading across different kinds of assets — not just more stocks — is the part people skip.
The years that prove it
These are the actual annual returns the simulator uses for the S&P 500, gold, and crude oil. Look at what disagrees with what.
| Year | S&P 500 | Gold | Crude oil |
|---|---|---|---|
| 2000 | -9% | -6% | +5% |
| 2001 | -13% | +2% | -26% |
| 2002 | -26% | +25% | +57% |
| 2008 | -58% | +6% | -54% |
| 2009 | +26% | +24% | +78% |
| 2013 | +32% | -28% | +7% |
In 2002 stocks fell sharply while gold and oil both rose. In 2008 stocks and oil collapsed together while gold held roughly flat — a reminder that "commodities" is not one thing. And in 2013 gold fell hard in a year stocks had one of their best runs. No single asset is the safe one; they take turns.
A portfolio split across these does worse than the best performer every single year, and that is the point. It also never posts the worst performer's year. Students find the first half obvious and the second half surprising.
The full asset menu, ranked by role
- S&P 500 index fund — the growth engine, and the benchmark everything else is judged against. Broad by construction, but still all-equity.
- Individual stocks — higher ceiling, higher floor. Useful in small doses; dangerous as the whole portfolio.
- Gold — produces no earnings, but frequently moves against equities in a panic. A hedge, not a growth asset.
- Crude oil — driven by supply shocks and global demand. Volatile in both directions, and as 2008 shows, not a reliable crash hedge.
- Certificates of deposit — a contracted fixed rate with an early-withdrawal penalty. Return is certain; the cost is that the money is locked.
- High-yield savings — small variable return, instantly available. The liquidity slot.
Where each of these figures comes from is documented on the methodology page.
Try it as an exercise
Run the simulator twice over the same historical window. First put everything into one company you like the look of. Then replay it split across the index fund, one or two stocks, a hedge, and a CD. Compare the ending values — but more importantly, compare the deepest drop each portfolio took along the way. The second run is usually calmer, and calm is what keeps people invested.
To push it further, the Sandbox lets you inject a crash into any year and watch which parts of a diversified portfolio absorb it.
This is an educational simulation using virtual money. It is not financial advice, and historical returns do not indicate future results.
Test it in the simulator
Twenty years of real market history, two strategies, about forty minutes.
Open the stock simulator