Key idea
Spreading money across many investments means no single failure can sink you. It is the closest thing to a free lunch in finance.
Diversification is the simple, powerful idea of not putting all your money into one investment. Spread it across many companies, sectors, and asset classes, and the poor performance of any one has a limited effect on the whole.
Why it works
Different investments rise and fall at different times. When one company or sector struggles, another may thrive; when equity falls, debt or gold may hold. By combining things that do not all move together, you reduce the overall bumpiness without necessarily giving up much return. That is why it is called the one free lunch in investing.
| Spread | Reduce | Keep |
|---|---|---|
| across companies & | the impact of any one | most of the return |
| sectors | failing |
The trap it protects against
Putting everything into a single stock, or a single sector you feel sure about, exposes you to that one bet completely. If it fails, so do you. History is full of "sure things" that collapsed. Diversification is the humble admission that you cannot know which one, so you hold many.
Mutual funds and index funds (later) are popular precisely because they deliver instant diversification: one purchase spreads your money across dozens or hundreds of companies.
Finished reading?
Marking this complete counts today, and your streak becomes day 1.