Beta
Beta is a measure of a security's volatility relative to the overall market, where a beta of 1.0 means the security moves with the market, above 1.0 means more volatile, and below 1.0 means less volatile.
Exam Tip
Beta = 1 means same volatility as market. >1 = more volatile. <1 = less volatile.
What is Beta?
Beta measures how much a security's price moves relative to the overall market (typically the S&P 500). It's a key metric for understanding systematic risk and portfolio construction.
Beta Values Explained
| Beta Value | Meaning | Example |
|---|---|---|
| β = 1.0 | Moves with market | Index funds |
| β > 1.0 | More volatile than market | Tech stocks, small caps |
| β < 1.0 | Less volatile than market | Utilities, consumer staples |
| β = 0 | No correlation to market | Some alternatives |
| β < 0 | Moves opposite to market | Gold (sometimes), inverse ETFs |
Examples
| Security Type | Typical Beta |
|---|---|
| S&P 500 Index | 1.0 (by definition) |
| High-growth tech stock | 1.5 - 2.0 |
| Utility company | 0.3 - 0.6 |
| Treasury bonds | ~0 |
How Beta is Used
Portfolio Construction:
- Higher beta = more aggressive portfolio
- Lower beta = more conservative portfolio
Expected Return (CAPM): Expected Return = Risk-Free Rate + Beta × (Market Return - Risk-Free Rate)
Limitations of Beta
- Based on historical data (past may not predict future)
- Assumes returns are normally distributed
- Doesn't capture all types of risk
- Can change over time
Beta vs. Standard Deviation
| Measure | What It Measures |
|---|---|
| Beta | Systematic (market) risk only |
| Standard Deviation | Total risk (systematic + unsystematic) |
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Related Terms
Systematic Risk (Market Risk)
SecuritiesSystematic risk is the inherent risk that affects the entire market or asset class, which cannot be eliminated through diversification and includes factors like interest rates, inflation, and recessions.
Diversification
GeneralDiversification is an investment strategy that spreads investments across various assets, sectors, or geographic regions to reduce risk without necessarily sacrificing returns.