What Is Diversification?
Diversification is the practice of spreading investments across different assets, sectors, or asset classes to reduce the impact of any single bad outcome on the overall portfolio.
The math works because uncorrelated assets don't all decline simultaneously. A portfolio holding 30 stocks across 10 sectors has lower volatility than a 1-stock concentration with the same expected return. This is the foundational insight of Modern Portfolio Theory.
Diversification has limits. In broad market crashes (2008, March 2020), correlations across stocks approach 1 — everything sells off together. True diversification requires uncorrelated asset classes: stocks, bonds, real estate, commodities, cash, international markets.
For active traders, the right level of diversification depends on strategy. Trend-following systems often need 10-30 simultaneous positions to capture statistical edge. Concentrated value investing might run 5-10 positions. Day trading is typically 1-3 positions at a time.
The trap to avoid: "diworsification" — adding positions just to feel safer, without actual risk reduction. Adding correlated assets (5 different mega-cap tech stocks) doesn't diversify much.
Related terms
- Risk Management — The systematic process of identifying and controlling exposure to losses.
- ETF (Exchange-Traded Fund) — A pooled investment vehicle that trades on stock exchanges like a regular stock.
- Drawdown — The peak-to-trough decline in account equity during a losing streak.