1 Portfolio and Capital Market Theory

Capital refers to the financial resources available to a company in the form of equity or debt.

Investors (creditors or company shareholders) provide borrowers or investees with medium- to long-term financing in the form of equity or debt capital

money is lent to borrowers on a short-term basis for a period of up to a year.

enable financial problems to be analyzed as clearly and coherently as possible. It implies a set of conditions where an equilibrium exists between supply and demand at the existing price for a commodity and market participants (buyers or sellers) cannot affect the price of the commodity

• frictionless

  • transactions do not incur costs or taxes, and all securities can be perfectly (in terms of information efficiency) shared and traded.

  • free of regulatory restrictions

• perfect competition

  • all market participants are “price takers”; their decisions and actions have no effect on market price.

• rational participants

  • entities operating within this market have full information and seek to act logically in their best

    interests.

• information effciency

• prospectuses

• market sector analyses

• economic and business reports

• company financial statements

• or reports in the financial press.

is a document about a company provided to potential investors; it has information about the company structure, securities for sale, business operations, risks, management, and financial status.

higher investment returns than other market participants.

a market which always has investors and sellers in sufficient numbers to meet mutual demand.

when all market participants have immediate access to the same information.

= past information

= past + public infor-

mation

= past + public+ private information

portfolio selection theory. It attempts to explain the frequently observed risk diversification behavior of investors (i.e., including a range of different securities/assets in their portfolio), how a portfolio should be diversified rationally, and how many securities or assets should be included in a portfolio (Markowitz, 1952). It is a theory of individual decision-making.

a function of its share of diversifiable variance or risk (unsystematic risk), and its share of non-diversifiable variance (systematic risk or market risk).

Unsystematic risk in a portfolio can be reduced by adding an asset that is likely to fluctuate in its performance in ways that do not fully correlate with the remainder of the portfolio.

The variance of return is thus minimized by the asset added to the portfolio.

• capital asset pricing model (CAPM) developed from the portfolio theory of Markowitz (1952)

• not about rational, individual decision-making

• about the way decisions aggregate to create market equilibrium

• field of application includes evaluation theory and practical company valuation

• attempts to identify that part of the overall risk of an investment that cannot be eliminated through diversification

• explains how to evaluate risky investment opportunities in the capital market

  
  

• Single-period transaction horizon (one year)

• Risk-averse and maximise profit

• Normal distribution of the returns

• Risk free investments exists

• Perfect capital market exists

• How can you value an investment with risk?

• What market price compensates for the risks taken?

To calculate beta, a regression analysis is performed for a certain period. For example, over a period of two years, the 104 weekly return figures of a stock are regressed with the corresponding returns of a market portfolio in the U.S., e.g., the Dow Jones stock market index. If this is graphed, with the x-axis representing the market rate of return and the y-axis the rate of return on the asset, the slope of the regression line corre-

sponds precisely to beta.

Perfect capital markets do not exist in practice. They are a theoretical construct designed to analyze problems from a financial and economic perspective and to suggest solutions. The core assumptions of a perfect capital market are (1) the market is frictionless (i.e., there are no transaction costs), (2) it is perfectly competitive, (3) all market participants behave rationally, and (4) the market is fully efficient in terms of availability of information (i.e., everyone has equal access to all possible sources of information).

Informational efficiency plays a key role in capital market theory. Informational efficiency means that all market participants possess all information relevant to valuing assets. A distinction is made between weak form, semi-strong form, and strong form informational efficiency.

Portfolio theory shows how an investor can create an optimized portfolio. According to the theory, unsystematic risk can be eliminated. Depending on the degree of correlation between two securities, adding a stock to a portfolio can minimize fluctuations in returns/yield. A diversification effect is only possible in the absence of a perfect positive correlation between the two securities.

The CAPM is an equilibrium pricing model for the capital market. It demonstrates how investments associated with risk are valued and shows which market price applies to an investment as compensation for the risk assumed.