• Skip to main content
  • Skip to secondary menu
  • Skip to primary sidebar
  • Skip to footer
  • Increase Sales
  • Effective Ads
  • Employee Selection
  • Leaderships Quality
  • Business Creativity
  • Small Start-ups

Googlesir

  • Employee Training
  • Marketing and Sales
  • Investment & Earning
  • Managerial Economics
  • Entrepreneurship and Career

Top 10 Key Assumptions of Modern Portfolio Theory

Updated on: June 26, 2020 Leave a Comment

Modern portfolio theory (MPT) is a theory of investment which tries to maximize portfolio expected return for a given amount of portfolio risk, or equivalently minimize risk for a given level of expected return, by carefully choosing the proportions of various assets.

key assumption of modern portfolio theory
key assumptions of modern portfolio theory

The mathematical framework of MPT makes many assumptions about investors and markets.

Some are explicit in the equations, such as the use of normal distributions to model returns.

Others are implicit, such as the neglect of taxes and transaction fees.

Page Contents

  • What are the Key assumptions of Modern Portfolio Theory?
    • 1. Asset Returns are (Jointly) Normally Distributed Random Variables
    • 2. Correlations between Assets are Fixed and Constant Forever
    • 3. All Investors Aim to Maximize Economic Utility
    • 4. All Investors are Rational and Risk Averse
    • 5. All Investors have Access to the Same Information at the Same Time
    • 6. Investors have an Accurate Conception of Positive Returns
    • 7. There are no Taxes or Transaction Costs
    • 8. Investors are Price Takers
    • 9. Every Investor has a Credit Limit
    • 10.  All Securities can be Divided into Parcels of Any Size

What are the Key assumptions of Modern Portfolio Theory?

None of these assumptions are entirely true, and each of they compromises modern portfolio theory to some degree:

1. Asset Returns are (Jointly) Normally Distributed Random Variables

In fact, it is frequently observed that returns in equity and other markets are not normally distributed.

Large swings occur in the market far more frequently than the normal distribution assumption would predict.

While the model can also be justified by assuming any return distribution which is jointly elliptical, all the joint elliptical distributions are symmetrical whereas asset returns empirically are not.

Different Types of Bonds – Which is Best Investment Bond for You.

2. Correlations between Assets are Fixed and Constant Forever

Correlations depend on systemic relationships between the underlying assets and change when relationships change.

For example, one country declaring war on another, or a general market crash.

During times of financial crisis, al assets tend to become positively correlated, because they all move (down) together.

In other words, MPT breaks down precisely when investors are ost in need of protection from risk.

3. All Investors Aim to Maximize Economic Utility

This is a key assumption of the efficient market hypothesis, upon which is MPT relies, in other words, to make as much money as possible regardless of any other considerations.

4. All Investors are Rational and Risk Averse

This is another assumption of the efficient market hypothesis, but it is clear from behavioral economics that market participants are not rational.

It does not allow for herd behavior or investors who will accept lower returns for higher risk.

Casino gambles clearly pay for risk, and it is possible that some stock traders will pay for risk as well.

5. All Investors have Access to the Same Information at the Same Time

This also comes from the efficient market hypothesis.

In fact, real markets contain information asymmetry.

Insider trading, and those who are simply better informed than others.

Key Factors to be Considered in Industry Analysis.

6. Investors have an Accurate Conception of Positive Returns

The probability beliefs of investors match the true distribution of returns.

A different possibility is that investors’ expectations are biased, causing market prices to be informationally inefficient.

This possibility is studied in the field of behavioral finance, which uses psychological assumptions to provide alternatives to the CAPM such as the overconfidence based asset pricing model.

7. There are no Taxes or Transaction Costs

Real financial products are subject both to taxes and transaction costs (such as broker fees), and taking these into account will after the composition of the optimum portfolio.

assumption of markowitz portfolio theory
assumption of Markowitz portfolio theory

These assumptions can be relaxed with more complicated versions of the model.

8. Investors are Price Takers

In reality, sufficiently large sales or purchases of individual assets can sift market prices for that asset and others (via cross elasticity of demand).

An investor may not even be able to assemble the theoretically optimal portfolio if the market moves too much while they are buying the required securities.

Advantages and Disadvantages of Commercial Banks.

9. Every Investor has a Credit Limit

Any investor can lend and borrow an unlimited amount at the risk-free rate of interest.

10.  All Securities can be Divided into Parcels of Any Size

In reality, fractional shares usually can not be bought or sold, and some assets have minimum order sizes.

Recommended for You:

  • What is the Process of Marketing Control?
  • Broad Types of Mutual Funds: Choose Right Mutual Fund
  • Main Sources of Venture Capital in India (With List)
  • Top Benefits of International Expansion of Business
  • Key Factors Affecting Capital Structure (Complete List)
  • Key Features and Importance Cost of Capital

Share Now:

  • Share
  • WhatsApp
  • Tweet

Leave a Comment

Reader Interactions

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Primary Sidebar

E-mail Newsletter

More to See

tools and techniques of career development of employees

21 Tools and Activities of Career Development of Employee

how to achieve workers participation in management

17 Primary Methods of Workers Participation in Management (WPM)

What are main reasons of industrial disputes

15 Reasons for the Occurrence of Industrial Conflicts

How to Make a Successful Participative Management

How to Make a Successful Participative Management

challenges of workers' participation in management

10 Basic Limitations of Workers Participation in Management

Footer

FREE Exclusive Notes via Email

Enter your email below to get access to Our All helpful Tips and Articles

Search

DMCA.com Protection Status

Join Us

  • Home
  • Contact Us
  • Privacy Policy
  • About us
  • Sitemap

© 2021Copyright www.Googlesir.com