What is CAPM?
As the name itself suggest, the Capital Asset Pricing Model (CAPM) is used for pricing the security with a given risk. This model describes the relationship between the expected return & risk in investing security. This article describes the advantages & disadvantages of CAPM.
CAPM shows that the expected return on a security is equal to a risk-free return plus a risk premium, which is based on the beta of the security. Assumptions of CAPM are the heart of the model.
Table of Contents
- What is CAPM?
- Formula of CAPM
- Advantages of CAPM
- Eliminates Unsystematic Risk
- Systematic Risk
- Investment Appraisal
- Ease of Use
- Disadvantages of CAPM
- Too Many Assumptions
- Assigning Values to CAPM Variables
- Ability to Borrow at Risk-free Rate
- Determination of Project Proxy Beta
- Conclusion
Formula of CAPM
Ra = Rf + Ba (Rm-Rf)
Where,
Ra = Expected return on a security
Rf = Risk-free rate
Rm = Expected return of the market
Ba = Beta of the security

Advantages of CAPM
Eliminates Unsystematic Risk
CAPM assumes that the investor holds a diversified portfolio, similar to a market portfolio. A diversified portfolio eliminates unsystematic (specific) risk.
Systematic Risk
CAPM considers systematic risk, which is left out of other return models, such as the dividend discount model. Systematic risk, also known as market risk, is an important variable because it is unforeseen and often cannot be mitigated as it is not fully expected.
Investment Appraisal
An investor can also use CAPM for investment appraisal compared to other rates; it offers a superior discount rate. This model clearly links required return & systematic risk.
Ease of Use
CAPM is a simplistic calculation that can be easily stress-tested to derive a range of possible outcomes. Those outcomes provide confidence around the required rate of returns.
Disadvantages of CAPM
Too Many Assumptions
The CAPM model is based on too many assumptions, which many criticize as unrealistic. Therefore, it may not provide the correct results.
Assigning Values to CAPM Variables
Risk-free Rate (Rf): The commonly accepted rate used as the Rf is the yield on short-term government securities. The problem with using this input is that the yield changes daily, creating volatility.
Return on the market (Rm): The return on a stock market is the sum of the average capital gain and the average dividend yield. The market return can be negative in a short-term market. As a result, the long-term market return is utilized. The other major drawback is that these returns are backward-looking & not futuristic.
Beta (B): Beta values are regularly published on all stock exchanges regularly for all listed companies. The issue here is that uncertainty arises in the value of the expected return because the value of beta is not constant but changes over time.
Ability to Borrow at Risk-free Rate
There are four major assumptions of CAPM. One of the assumptions is that investors can borrow & lend the funds at a risk-free rate. This assumption is unrealistic for the real world. Individual investors are unable to borrow or lend at the same return as the US government.
Therefore expected return calculated by the CAPM model may not be correct in this situation.
Determination of Project Proxy Beta
The problem may arise in using the CAPM to calculate a project-specific discount rate. Generally, equity beta & portfolio/investment beta are different. Therefore, the company needs to find a proxy beta for the project.
However, finding accurate proxy beta might be difficult and can affect the reliability of the outcome.
Conclusion
Research has shown the CAPM stands up well to criticism, although attacks against it have been increasing in recent years. Until something better presents itself, the CAPM remains a very useful item in the financial management toolkit.
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Sanjay Bulaki Borad
Sanjay Borad is the founder & CEO of eFinanceManagement. He is passionate about keeping and making things simple and easy. Running this blog since 2009 and trying to explain "Financial Management Concepts in Layman's Terms".
FAQs
What are the advantages of using CAPM? ›
Advantages of the CAPM Model
The CAPM is a simple calculation that can be easily stress-tested to derive a range of possible outcomes to provide confidence around the required rates of return.
The major drawback of CAPM is it is difficult to determine a beta. This model of return calculation requires investors to calculate a beta value that reflects the security being invested in. It can be difficult and time-consuming to calculate an accurate beta value. In most cases, a proxy value for beta is used.
Why is CAPM negative? ›Some equilibrium prices in CAPM may be negative because of nonmonotonicity of preferences. We identify several sets of sufficient conditions for prices to be positive. The central conditions impose bounds on the investors' risk aversion.
What are the assumptions and limitations of CAPM model? ›The CAPM has serious limitations in real world, as most of the assumptions, are unrealistic. Many investors do not diversify in a planned manner. Besides, Beta coefficient is unstable, varying from period to period depending upon the method of compilation. They may not be reflective of the true risk involved.
What is CAPM and its assumptions? ›The Capital Asset Pricing Model (CAPM) is a model that describes the relationship between the expected return and risk of investing in a security. It shows that the expected return on a security is equal to the risk-free return plus a risk premium, which is based on the beta of that security.
Why is CAPM better than DDM? ›The capital asset pricing model (CAPM) is considered more modern than the DDM and factors in market risk. The value of a security in the CAPM is determined by the risk free rate (most likely a government bond) plus the volatility of a security multiplied by the market risk premium.
Which are reasons that it is difficult to test the CAPM? ›Testing the CAPM is difficult because of lack of theoretical or empirical clarity on what constitutes the market portfolio. Some argue that it is impossible to test the CAPM because empirical results test whether the market portfolio proxy is efficient but tell nothing about the CAPM.
What is the difference between WACC and CAPM? ›The Difference Between CAPM and WACC
The CAPM is a formula for calculating cost of equity. The cost of equity is part of the equation used for calculating the WACC. The WACC is the firm's cost of capital which includes the cost of the cost of equity and cost of debt.
The Capital Asset Pricing Model (CAPM) estimates the expected return on an investment given its systematic risk. The cost of equity – i.e. the required rate of return for equity holders – is calculated using the CAPM.
What is CAPM and why is it important? ›CAPM (Capital Asset Pricing Model) takes into account the systematic risk as the unsystematic risk can be diversified. It creates a theoretical relationship between risk and the rate of return from a portfolio.
Can CAPM return negative? ›
Don't forget the models produce a negative market return is impossible because you are in an anticipation environment (for instance with CAPM). In an anticipation world, the prime of market risk (RM-R0) can not be negative.
Is CAPM a single factor model? ›CAPM is the one-factor model for investment returns. Next week we will add two more factors that help explain more of the variance of specific investments against general market returns.
Is CAPM used in real life? ›The capital asset pricing model (CAPM) is widely used within the financial industry, especially for riskier investments. The model is based on the idea that investors should gain higher yields when investing in more high-risk investments, hence the presence of the market risk premium in the model's formula.
Does CAPM assume efficient market? ›The CAPM modeled by Sharpe, however, has no such duality—there is one market portfolio and one beta for each security in the economy. In Sharpe's CAPM world, markets are perfectly efficient, and everyone has the same information.
What is the relationship of risk and return as per CAPM? ›The CAPM contends that the systematic risk-return relationship is positive (the higher the risk the higher the return) and linear. If we use our common sense, we probably agree that the risk-return relationship should be positive.
Is CAPM real or nominal? ›You estimate the cost of equity using the capital asset pricing model. The cash flows are in real terms, the nominal risk-free rate for the short-term Japanese government bills is 1.5%, the 10-year government bonds rate is 2.5% and inflation rate is 0.7%.
Does CAPM predict returns? ›The Capital Asset Pricing Model (CAPM) is the most commonly used tool for predicting stock returns. It is taught in business schools, and it has been used by investors for decades.
What is the risk-free rate for CAPM? ›Risk-Free Rate Component in CAPM
The risk-free rate serves as the minimum rate of return, to which the excess return (i.e. the beta multiplied by the equity risk premium) is added. The equity risk premium (ERP) is calculated as the average market return (S&P 500) minus the risk-free rate.
The CAPM model values the stock from the perspective of market risk, while the DDM model evaluates the stock by seeking the present value of future dividends. These two models are used as our research methods to study whether stocks are overvalued.
Does CAPM include unsystematic risk? ›(No measure of unsystematic risk appears in the risk premium, of course, for in the world of CAPM diversification has eliminated it.) In the freely competitive financial markets described by CAPM, no security can sell for long at prices low enough to yield more than its appropriate return on the SML.
How do you use CAPM to value stock? ›
How is CAPM calculated? To calculate the value of a stock using CAPM, multiply the volatility, known as “beta,” by the additional compensation for incurring risk, known as the “Market Risk Premium,” then add the risk-free rate to that value.
What is the passing mark for CAPM? ›CAPM Exam Passing Marks
CAPM certificate exam does not have any fixed passing marks. However, it is believed that 61% will guarantee your success. Although it is not confirmed, this is why you should aim for 70%. It is said that having 61% of marks can help you clear your CAPM exam.
Assumptions of Capital Market Theory, Markowitz-Style
The following assumptions apply to the base theory: All investors are risk-averse by nature. Investors have the same time period to evaluate information. There is unlimited capital to borrow at the risk-free rate of return.
Using CAPM to determine the cost of debt
The CAPM can be used to derive a required return as long as the systematic risk of an investment is known. Then, the post tax cost of debt is kd (1-T) as usual.
The WACC is the minimum return that a company must earn on its investment projects to satisfy its owners and creditors. CAPM is a model that calculates the expected return of an investment based on its beta, which is a measure of the volatility of the investment.
Does CAPM use asset beta or equity beta? ›The beta of a company measures how the company's equity market value changes with changes in the overall market. It is used in the capital asset pricing model (CAPM) to estimate the return of an asset.
What are the components of CAPM? ›This is the capital asset pricing model (CAPM). The expected return on a risky asset thus has three components. The first is the pure time value of money (Rf), the second is the market risk premium, [E(Rm) - Rf], and the third is the beta for that asset, Bi.
Is CAPM cost of equity? ›Cost of equity is the return that a company requires for an investment or project, or the return that an individual requires for an equity investment. The formula used to calculate the cost of equity is either the dividend capitalization model or the CAPM.
Who introduced CAPM? ›I.
Sharpe (1964) and Lintner (1965) introduced the Capital Asset Pricing Model (CAPM) to investigate the relationship between the expected return and the systematic risk. From the day CAPM was developed, it was regarded as one of the primary models to price an equity or a bond portfolio.
The APT allows for multiple risk factors to be included within the data set being examined instead of excluding them. This makes it possible for individual investors to see more information about why certain stock returns are moving in specific ways.
What are the main conclusions of the Capital Asset Pricing Model? ›
These practical implications of the CAPM follow from two basic CAPM conclusions: (1) that the market portfolio—that is, a portfolio that holds securities in proportion to their market capitalization—is an efficient portfolio and (2) that an asset's expected return has a simple (linear) relationship to its beta.
What is the difference between WACC and CAPM? ›The Difference Between CAPM and WACC
The CAPM is a formula for calculating cost of equity. The cost of equity is part of the equation used for calculating the WACC. The WACC is the firm's cost of capital which includes the cost of the cost of equity and cost of debt.
Testing the CAPM is difficult because of lack of theoretical or empirical clarity on what constitutes the market portfolio. Some argue that it is impossible to test the CAPM because empirical results test whether the market portfolio proxy is efficient but tell nothing about the CAPM.
What is better than CAPM? ›The arbitrage pricing theory is an alternative to the CAPM that uses fewer assumptions and can be harder to implement than the CAPM. While both are useful, many investors prefer to use the CAPM, a one-factor model, over the more complicated APT, which requires users to quantify multiple factors.
Is CAPM a single factor model? ›CAPM is the one-factor model for investment returns. Next week we will add two more factors that help explain more of the variance of specific investments against general market returns.
What is the major difference between CAPM and APT? ›The major difference between the capital asset pricing model (CAPM) and arbitrage pricing model (APT) is CAPM uses a single systematic risk factor to explain an asset's return whereas APT uses multiple systematic factors.
Is CAPM used in real life? ›CAPM cannot be used in isolation because it necessarily simplifies the world of financial markets. But financial managers can use it to supplement other techniques and their own judgment in their attempts to develop realistic and useful cost of equity calculations.
What are the essential elements of CAPM? ›CAPM Equation Assumptions
The formula is comprised of three components: Risk-Free Rate (rf): The return received from risk-free investments — most often proxied by the 10-year treasury yield. Beta (β): The measurement of the volatility (i.e. systematic risk) of a security compared to the broader market (S&P 500)
This is the capital asset pricing model (CAPM). The expected return on a risky asset thus has three components. The first is the pure time value of money (Rf), the second is the market risk premium, [E(Rm) - Rf], and the third is the beta for that asset, Bi.
Can CAPM be used for debt? ›Using CAPM to determine the cost of debt
The CAPM can be used to derive a required return as long as the systematic risk of an investment is known. Then, the post tax cost of debt is kd (1-T) as usual.
Does CAPM use asset beta or equity beta? ›
The beta of a company measures how the company's equity market value changes with changes in the overall market. It is used in the capital asset pricing model (CAPM) to estimate the return of an asset.
Is a high CAPM good? ›If the estimate is higher than the current market value, then the stock is currently a bargain – but if it's lower, then the stock is being overvalued. CAPM gives you a good, comprehensive look at the risk versus rate of return on an investment, especially a stock.