WealthTrails
Back to Understanding Risk & Volatility
Checkpoint 2 of 4

Measuring Volatility

5 min

Numbers help us compare risk across investments. Standard deviation and beta are two key metrics every investor should understand.

Standard Deviation

Standard deviation measures how much returns vary from the average. A stock with 20% standard deviation swings much more than one with 10%. Higher standard deviation = more volatile. Most stock market returns fall within 1-2 standard deviations of the average.

Low Volatility
Bond fund with 5% std dev
Returns typically range from -5% to +15%
Medium Volatility
S&P 500 with 15% std dev
Returns typically range from -15% to +25%
High Volatility
Tech stock with 30% std dev
Returns typically range from -30% to +50%

Beta: Relative to the Market

Beta measures how much an investment moves relative to the overall market. A beta of 1.0 means it moves with the market. Beta of 1.5 means it moves 50% more (up and down). Beta of 0.5 means it moves half as much. Negative beta moves opposite the market.

Using Beta in Practice

Aggressive investors might seek high-beta stocks for amplified gains in bull markets. Conservative investors prefer low-beta investments for stability. Utilities and consumer staples typically have low betas; tech and small caps have high betas.

Expected Return = Risk-Free Rate + Beta × (Market Return - Risk-Free Rate)
Example:
If market returns 10%, risk-free is 4%, and beta is 1.5: Return = 4% + 1.5 × (10% - 4%) = 13%
Key Takeaways
  • Standard deviation measures total volatility of returns
  • Beta measures volatility relative to the market (1.0 = same as market)
  • High beta amplifies gains AND losses compared to the market
Knowledge Check

Answer these questions to complete the checkpoint and unlock the next one.

1. A stock has a beta of 1.3. If the market rises 10%, what would you expect?

2. What does a low standard deviation indicate?