R-Squared
R-Squared
A statistical measure indicating the percentage of a portfolio's movements that can be explained by movements in a benchmark index. Ranges from 0 to 1 (or 0% to 100%), with higher values indicating stronger correlation. High R-squared (above 0.85) means beta is a reliable predictor of portfolio behavior; low R-squared indicates significant unsystematic risk that beta does not capture.
An S&P 500 index fund typically has an R-squared near 1.0 (100%) relative to the S&P 500, meaning virtually all its movements are explained by the index. An actively managed small-cap fund might have R-squared of 0.70 (70%) relative to the S&P 500, meaning 30% of its movement is due to factors other than broad market movements (manager stock selection, sector tilts, company-specific events).
Students often think high R-squared is always better, but it simply indicates how closely a portfolio tracks its benchmark. Low R-squared does not mean poor performance; it means the portfolio behaves differently from the benchmark (which may be intentional for active managers). Also commonly confused with correlation coefficient: R-squared is the square of correlation, always positive, and represents explained variance.
How This Is Tested
- Interpreting R-squared values to determine how much of portfolio movement is explained by benchmark
- Understanding the relationship between R-squared and beta reliability (high R-squared makes beta more meaningful)
- Distinguishing between systematic risk (measured by beta when R-squared is high) and unsystematic risk
- Recognizing that low R-squared means significant portfolio movement comes from non-benchmark factors
- Identifying when R-squared is too low to rely on beta for predicting portfolio behavior
- Comparing R-squared values between actively managed funds and index funds
Regulatory Limits
| Description | Limit | Notes |
|---|---|---|
| R-squared range | 0 to 1 (or 0% to 100%) | Cannot be negative; 1.0 (100%) indicates perfect correlation with benchmark |
| High R-squared threshold | Above 0.85 (85%) | Generally considered highly correlated to benchmark; beta is reliable predictor |
| Low R-squared threshold | Below 0.70 (70%) | Beta becomes less reliable; significant unsystematic risk present |
Example Exam Questions
Test your understanding with these practice questions. Select an answer to see the explanation.
Lisa, a portfolio manager, is evaluating two equity mutual funds for a client who wants exposure to large-cap stocks. Fund A has a beta of 1.15 and R-squared of 0.95 relative to the S&P 500. Fund B has a beta of 1.15 and R-squared of 0.65 relative to the S&P 500. Both funds have similar 5-year returns. Which statement best describes the difference between these funds?
B is correct. Fund A's R-squared of 0.95 (95%) means that 95% of its movement is explained by S&P 500 movements, indicating it closely tracks the benchmark with minimal deviation. Fund B's R-squared of 0.65 (65%) means only 65% of its movement is explained by the S&P 500, with 35% coming from other factors like manager stock selection, sector tilts, or company-specific events. Both have the same beta (1.15), but Fund B's beta is less reliable as a predictor because of the significant non-market influences.
A is incorrect because R-squared does not measure volatility; both funds have identical beta (1.15), which indicates similar systematic volatility. Higher R-squared indicates correlation strength, not volatility level. C is incorrect because lower R-squared does not necessarily mean better diversification; it means the portfolio behaves differently from the benchmark, which could be due to concentration risk, active management, or different market segment exposure. D is incorrect because lower R-squared actually makes beta LESS reliable, not more reliable. When R-squared is low (below 0.70-0.85), beta becomes a poor predictor of portfolio behavior because much of the portfolio's movement is not explained by market movements.
The Series 65 exam tests your ability to interpret R-squared in conjunction with beta to assess portfolio characteristics and risk. Understanding that high R-squared makes beta reliable while low R-squared indicates significant non-market influences is critical for portfolio analysis and setting client expectations about how a fund will behave relative to its benchmark.
What is the range of possible values for R-squared?
D is correct. R-squared can be expressed either as a decimal from 0 to 1.0 or as a percentage from 0% to 100%; both representations are mathematically equivalent and commonly used. An R-squared of 0.85 is the same as 85%. The value represents the proportion (or percentage) of a portfolio's variance that is explained by the benchmark's variance.
A is incorrect because R-squared cannot be negative. While the correlation coefficient ranges from -1.0 to +1.0, R-squared is the square of correlation, which eliminates negative values. An R-squared of 0 means no linear relationship with the benchmark, and 1.0 (or 100%) means perfect positive correlation. B alone is incomplete because while technically correct for the decimal representation, R-squared is also commonly expressed as a percentage (0% to 100%). C alone is incomplete for the same reason; the percentage scale (0% to 100%) is correct but doesn't acknowledge the decimal representation.
The Series 65 exam frequently presents R-squared values in both decimal and percentage formats. You must recognize that 0.85 and 85% are identical values, and understand that R-squared is always non-negative (unlike correlation coefficient which can be negative). This knowledge is essential for correctly interpreting fund performance statistics and benchmark comparisons.
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Access Free BetaA technology sector fund has an R-squared of 0.42 when compared to the S&P 500 index. What does this indicate about the fund?
C is correct. An R-squared of 0.42 (42%) means that only 42% of the fund's price movements can be explained by movements in the S&P 500, with the remaining 58% due to other factors (sector-specific trends, individual stock selection, etc.). This low R-squared indicates that beta relative to the S&P 500 would not be a reliable predictor of the fund's behavior, since most of its movement is driven by non-market factors. This is expected for a sector fund compared to a broad market index.
A is incorrect because R-squared of 0.42 indicates that the correlation coefficient is approximately 0.65 (the square root of 0.42), not 42%. R-squared is the square of the correlation coefficient. B is incorrect because R-squared does not predict the magnitude of declines; that is determined by beta. R-squared only tells you how much of the fund's variance is explained by the benchmark's variance. D is incorrect because R-squared measures statistical relationship (explained variance), not portfolio composition. A fund could have high R-squared with a benchmark without holding any of the same stocks, or vice versa.
The Series 65 exam tests your ability to correctly interpret R-squared values and understand what they mean for portfolio analysis. Low R-squared (typically below 0.70) indicates that beta is unreliable and that the portfolio has significant exposure to factors beyond broad market movements. This is critical for understanding sector funds, international funds, and actively managed strategies.
All of the following statements about R-squared are accurate EXCEPT
C is correct (the EXCEPT answer). R-squared does NOT range from -1.0 to +1.0; it always ranges from 0 to 1.0 (or 0% to 100%). R-squared is the square of the correlation coefficient, and squaring any number always produces a non-negative result. Even if correlation is negative (inverse relationship), R-squared is still positive because squaring eliminates the sign. For example, a correlation of -0.8 produces R-squared of 0.64 (64%), not negative.
A is accurate: R-squared specifically measures the proportion (percentage) of a portfolio's variance that can be explained by variance in the benchmark index. An R-squared of 0.80 means 80% of the portfolio's movement is explained by the benchmark. B is accurate: when R-squared is high (typically above 0.85 or 85%), the portfolio moves closely with the benchmark, making beta a reliable predictor of how the portfolio will respond to market movements. D is accurate: low R-squared (typically below 0.70) indicates that much of the portfolio's movement cannot be explained by the benchmark, suggesting significant unsystematic (non-market) risk from factors like sector concentration, individual stock selection, or style tilts.
The Series 65 exam tests your ability to distinguish between R-squared and correlation coefficient. While correlation can be negative (indicating inverse relationship), R-squared is always non-negative because it represents explained variance (the square of correlation). This distinction is critical for correctly interpreting portfolio statistics and understanding benchmark relationships.
An investment adviser is analyzing a mid-cap growth fund with the following statistics relative to the Russell Midcap Growth Index:
Beta: 1.20
R-squared: 0.88
Which of the following statements are accurate?
1. The fund is more volatile than the Russell Midcap Growth Index
2. Approximately 88% of the fund's movement can be explained by movements in the Russell Midcap Growth Index
3. The fund's beta is a reliable predictor of its behavior relative to the benchmark
4. The fund has eliminated most unsystematic risk through diversification
B is correct. Statements 1, 2, and 3 are accurate, but statement 4 is not necessarily true.
Statement 1 is TRUE: Beta of 1.20 means the fund is 20% more volatile than the Russell Midcap Growth Index. When the index moves 10%, the fund would be expected to move approximately 12%. Higher beta indicates greater systematic volatility relative to the benchmark.
Statement 2 is TRUE: R-squared of 0.88 (88%) means that 88% of the fund's price variance can be explained by variance in the Russell Midcap Growth Index. The remaining 12% is explained by other factors like individual stock selection, sector tilts, or timing differences.
Statement 3 is TRUE: R-squared of 0.88 is above the 0.85 threshold generally considered to indicate high correlation. This high R-squared means the fund tracks the benchmark closely, making the beta of 1.20 a reliable predictor of how the fund will behave when the benchmark moves.
Statement 4 is FALSE: While the high R-squared indicates the fund moves closely with its benchmark, this does not necessarily mean unsystematic risk has been eliminated. The fund could still have significant concentration in individual stocks or sectors within the mid-cap growth universe. R-squared measures explained variance relative to the benchmark, not diversification quality. A concentrated portfolio of 15 mid-cap growth stocks could have high R-squared to the index but still carry substantial unsystematic (company-specific) risk.
The Series 65 exam tests comprehensive understanding of how beta and R-squared work together to describe portfolio characteristics. You must recognize that high R-squared validates beta as a predictor, that beta measures relative volatility, and that R-squared measures explained variance (not diversification quality). This integrated analysis is essential for portfolio evaluation and client communication.
💡 Memory Aid
R-Squared = Reliability score for beta. High R² (near 100%) = portfolio is a copycat of benchmark (beta is trustworthy). Low R² (below 70%) = portfolio does its own thing (beta is unreliable, significant non-market risk). Think: R² answers "Can I rely on beta?"
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Where This Appears on the Exam
This term is tested in the following Series 65 exam topics: