Portfolio Diversification Basics
Diversification spreads exposure across investments whose outcomes are not perfectly aligned. It can reduce some company-specific risk but cannot eliminate broad market losses or guarantee a return.
How it works
Look through fund holdings and consider sector, country, currency, asset class and issuer concentration. Correlation measures historical co-movement under a chosen sample; it is not a permanent protection. Portfolio risk also depends on weights, volatility and the investor’s cash needs.
Worked example
A two-position portfolio has 50% in each company. If one falls 40% while the other is unchanged, the portfolio falls 20% before costs. With 10% in the first and 90% unchanged elsewhere, that company contributes a 4% decline. If all holdings fall together, both portfolios can still suffer substantially.
Amounts, prices and scenarios are fictional teaching examples. They exclude any effects not explicitly stated and are not trade recommendations.
Limits and common mistakes
Highly correlated funds can look diversified by name. Stress correlations can rise when liquidity disappears. Adding many small positions can increase costs without materially reducing the largest shared exposure.
Knowledge check
Can diversification remove market risk entirely?
Read the explanation
No. It can reduce the effect of individual failures and some imperfectly correlated risks, but shared economic shocks can affect many holdings at once.
References and further reading
- SEC Investor.gov: stocks, ownership and risks
- SEC: company filings and financial reports
- SEC: beginners’ guide to financial statements
These sources explain the underlying concepts and specifications. They do not endorse QBMFX Academy. Check the relevant market, protocol version and reporting rules before applying an example.