Lesson 5 of 8 10 min
Diversification
Why owning many things reduces the damage any one can do.
Written by Mateo LermaLast reviewed 3 sourcesEditorial standards
All lessons in Investing
Step 1: The lesson
What is diversification, and why does it matter?
Diversification means spreading your money across many different investments, so no single one can sink you. It's the investing version of "don't put all your eggs in one basket."
Some risks belong to a single company — a failed product, a scandal, a new competitor. Diversification shrinks those risks dramatically, because one company's bad year is a small slice of the whole.
Other risks hit almost everything at once — recessions, interest rate changes, market panics. Diversification can't remove those. It reduces risk; it doesn't eliminate it.
- Across companies: many businesses, not a few.
- Across industries: tech, health care, energy, consumer goods, and more.
- Across asset types: stocks and bonds behave differently.
- Across countries: U.S. and international markets.
Owning a lot of one thing isn't diversified
Five tech companies is still a bet on tech. Your employer's stock, if you work there, is doubly risky: a bad year could hit your job and your investments together.
Step 2: See it
Portfolio loss when one company drops 50%
If all your money is in one company and it drops 50%, your portfolio loses 50%. If your money is split evenly across 20 companies and one drops 50%, your portfolio loses 2.5%.
Step 3: Real-world example
One basket vs. twenty
Two investors each put in $1,000. Then one company in the market has a disastrous year and drops 50%.
- Investor A put everything in that company: $1,000 → $500.
- Investor B split $50 across 20 companies, including that one: she loses $25, or 2.5%, from that stock.
Investor B also gave up the chance of a huge gain from one company. That's the trade: diversification gives up lottery-ticket upside to avoid wipeouts.
Step 4: Knowledge check
Quiz: Diversification (3 questions)
Answer each question, then check your answer to see the explanation. Retake it as many times as you like.
Question 1 of 3
Step 5: Summary
Summary: Diversification
Diversification spreads money across many investments so no single failure can do much damage. It sharply reduces company-specific risk, but it can't prevent market-wide drops. Spread across companies, industries, asset types, and countries.
Step 6: What you should remember
Key takeaways: Diversification
- Diversification = don't put all your eggs in one basket.
- It shrinks single-company risk — not market-wide risk.
- Many companies in one industry isn't truly diversified.
- It trades lottery-ticket upside for protection from wipeouts.
Key terms in this lesson
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Sources and further reading
Rules, rates, and official figures in this lesson are based on these sources. People and numbers in examples are hypothetical.
- 1.Asset Allocation and Diversification (opens in a new tab)
Investor.gov (U.S. Securities and Exchange Commission) · investor.gov
- 2.Diversification (opens in a new tab)
Investor.gov (U.S. Securities and Exchange Commission) · investor.gov
- 3.Beginners' Guide to Asset Allocation, Diversification, and Rebalancing (opens in a new tab)
U.S. Securities and Exchange Commission · sec.gov
Cite this lesson
Financial Literacy Club. (2026, September). Diversification. https://learnwithflc.org/courses/investing/diversification
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