Skip to content

NISM-Series-XXI-A: Portfolio Management Services (PMS) Distributors · Investments

Risk and Return Concepts for NISM PMS Distributors

Updated 11 October 2026 · Fact-checked

Return is what you earn on an investment, measured as absolute return or CAGR. Risk is the chance actual return differs from expected return. Systematic risk affects the whole market and cannot be diversified away. Unsystematic risk is specific to a company or sector. Standard deviation measures total risk; beta measures market-related risk.

Understand Risk and Return Concepts

Return is the gain or loss on an investment, from price change plus income such as dividends or interest. You can show it in rupees or as a percentage of the amount invested.

Risk is the uncertainty of return. A risky investment is one where the actual outcome can be far from what you expected, on the upside or the downside. Higher expected return usually comes with higher risk. This is the risk-return trade-off.

Risk has two parts. Systematic risk (market risk) comes from factors that hit the whole market: interest rate changes, inflation, recession, policy shifts, geopolitical events. You cannot remove it by holding more stocks. Unsystematic risk (specific risk) comes from one company or industry: poor management, a product failure, a regulatory action on one sector. You can reduce it by diversifying across many securities.

Two measures matter most. Standard deviation shows how widely returns are spread around their average. It captures total risk, both systematic and unsystematic. Beta shows how sensitive a security or portfolio is to market moves. It captures only systematic risk. The market (benchmark) has a beta of 1.

For return, absolute return is the total percentage gain over the whole period and ignores time. CAGR (compound annual growth rate) converts a multi-year gain into a smooth yearly rate. Use CAGR to compare investments held for different periods.

Key formulas to remember

Absolute return
Absolute return (%) = (Ending value − Beginning value + Income received) ÷ Beginning value × 100
Ignores the time period. Without income, it is just the change in value over the starting value.
CAGR
CAGR = (Ending value ÷ Beginning value)^(1 ÷ n) − 1
n is the number of years. Valid when there are no interim cash flows.
Total risk
Total risk = Systematic risk + Unsystematic risk
Diversification removes only the unsystematic part.
Average (mean) return
Mean = Σ returns ÷ number of observations
First step in finding standard deviation.
Variance and standard deviation (sample)
Variance = Σ (return − mean)² ÷ (n − 1); Standard deviation = √Variance
Use n instead of n − 1 if the question says population or treats the data as complete.
Beta
Beta = Covariance (asset, market) ÷ Variance (market)
Beta of 1 moves with the market; above 1 is more volatile; below 1 is less volatile.
Expected market-linked move
Expected change in portfolio ≈ Beta × Change in market
A simple approximation used in questions.

How to solve Risk and Return Concepts questions

Use this method for any risk and return question, whether it is a calculation or a definition.

  1. 1Identify what is asked: return, risk type, or a risk measure.
  2. 2If it is a risk type, ask: does this factor affect the whole market or only one firm or sector? Whole market means systematic; specific means unsystematic.
  3. 3If it is return, check the time period. More than one year and a comparison needed points to CAGR; total gain over the period points to absolute return.
  4. 4For standard deviation, find the mean, then the deviations, square them, add them, divide by n − 1 (or n if stated), and take the square root.
  5. 5For beta, compare with 1. Multiply beta by the market move to estimate the portfolio move.
  6. 6Check whether the question asks about total risk (standard deviation) or market risk (beta).
  7. 7Eliminate options with wrong units or direction, such as a negative variance or a percentage above the possible range.

Quickest way: Shortcut for risk and return questions

When to use it: Use it when time is short and the question is mostly conceptual or has simple numbers.

  1. Whole market factor? Pick systematic. One company or sector factor? Pick unsystematic.
  2. Diversification is the answer for unsystematic risk. There is no diversification fix for systematic risk.
  3. Standard deviation means total risk. Beta means market risk only.
  4. For CAGR, test the options: a 2-year doubling gives about 41.4%, not 50%.
  5. Beta times market move gives the quick estimate. Beta 1.2 and market up 10% gives about 12%.

Common mistakes in Risk and Return Concepts

  • Saying diversification removes all risk.

    Students remember that diversification reduces risk and stop there.

    Fix: Diversification removes only unsystematic risk. Systematic risk stays.

  • Treating beta as total risk.

    Both beta and standard deviation are called risk measures.

    Fix: Beta captures only market-related risk. Standard deviation captures total risk.

  • Dividing absolute return by years to get annual return.

    It looks simple and gives a rough answer.

    Fix: Use CAGR for annualised return. Simple division ignores compounding.

  • Forgetting to take the square root after finding variance.

    Students stop at the last calculation step.

    Fix: Standard deviation is √Variance. Check that your answer is in the same unit as returns, in per cent.

  • Mixing sample and population divisors.

    Both forms appear in textbooks.

    Fix: Read the question. Use n − 1 for a sample, n if it treats the data as the whole population.

  • Calling a high-beta stock safer in falling markets.

    Students link a high number with a good outcome.

    Fix: Beta above 1 magnifies moves in both directions. It falls more than the market when the market falls.

Worked examples

Example 1

A portfolio grows from ₹10,00,000 to ₹14,40,000 over 2 years with no interim cash flows. What are its absolute return and CAGR?

Show the solution
  1. Absolute return = (14,40,000 − 10,00,000) ÷ 10,00,000 × 100 = 44%.
  2. Growth ratio = 14,40,000 ÷ 10,00,000 = 1.44.
  3. CAGR = 1.44^(1/2) − 1 = 1.2 − 1 = 0.20.
  4. CAGR = 20% per year.

Answer: Absolute return is 44%; CAGR is 20% per year.

Example 2

A security gave annual returns of 10%, 14% and 12% over three years. What is its sample standard deviation?

Show the solution
  1. Mean = (10 + 14 + 12) ÷ 3 = 12%.
  2. Deviations: −2, +2, 0.
  3. Squared deviations: 4, 4, 0. Sum = 8.
  4. Sample variance = 8 ÷ (3 − 1) = 4.
  5. Standard deviation = √4 = 2%.

Answer: Sample standard deviation is 2%.

Exam tips

  • Expect definition questions asking which risk can be diversified. The answer is unsystematic.
  • Match the example to the risk type: interest rate change or inflation is systematic; a company's labour strike is unsystematic.
  • Check if the question says total risk or market risk before choosing between standard deviation and beta.
  • Read the divisor instruction in standard deviation questions, and check your final figure against the options before moving on.
  • PMS Distributors carries negative marking of 10% of the marks for a question, so eliminate clearly wrong options and then answer.

Practice questions from Investments

Risk and Return Concepts in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Risk and Return Concepts: frequently asked questions

What is the difference between systematic and unsystematic risk?

Systematic risk affects the whole market, such as interest rate or inflation changes, and cannot be diversified away. Unsystematic risk is specific to a company or sector and can be reduced by diversification.

What is the difference between absolute return and CAGR?

Absolute return is the total gain over the whole holding period and ignores time. CAGR is the smoothed yearly compound rate, so it lets you compare investments held for different periods.

What does beta mean in portfolio management?

Beta measures how sensitive a security or portfolio is to market movements. A beta of 1 moves with the market, above 1 moves more, and below 1 moves less.

How do I calculate standard deviation of returns?

Find the mean return, subtract it from each return, square the differences, add them, divide by n − 1 for a sample, and take the square root. The result shows how widely returns spread around the mean.