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Business activities entail a variety of
risks. For convenience, we distinguish
between different categories of risk: market risk,
credit risk,
liquidity risk,
etc. Although such categorization is convenient, it is only informal.
Usage and definitions vary. Boundaries between categories are blurred. A
loss due to widening credit spreads may reasonably be called a market loss
or a credit loss, so market risk and credit risk overlap. Liquidity risk
compounds other risks, such as market risk and credit risk. It cannot be
divorced from the risks it compounds.
An important but somewhat ambiguous distinguish is that
between market risk and
business risk. Market risk is exposure to
the uncertain market value of a portfolio. A trader holds a portfolio of
commodity forwards. She knows
what its market value is today, but she is uncertain as to its market
value a week from today. She faces market risk. Business risk is exposure
to uncertainty in economic value that cannot be marked-to-market. The
distinction between market risk and business risk parallels the
distinction between market-value accounting and book-value accounting.
Suppose a New England electricity wholesaler is long a forward contract
for on-peak electricity delivered over the next 3 months. There is an
active forward market for such electricity, so the contract can be marked
to market daily. Daily profits and losses on the contract reflect market
risk. Suppose the firm also owns a power plant with an expected useful
life of 30 years. Power plants change hands infrequently, and electricity
forward curves don’t exist out to 30 years. The plant cannot be marked to
market on a regular basis. In the absence of market values, market risk is
not a meaningful notion. Uncertainty in the economic value of the power
plant represents business risk.
The distinction between market risk and business risk is
ambiguous because there is a vast "gray zone" between the two. There are
many instruments for which markets exist, but the markets are illiquid.
Mark-to-market values are not usually available, but
mark-to-model values
provide a more-or-less accurate reflection of fair value. Do these
instruments pose business risk or market risk? The decision is important
because firms employ fundamentally different techniques for managing the
two risks.
Business risk is managed with a long-term focus.
Techniques include the careful development of business plans and
appropriate management oversight. book-value accounting is generally used,
so the issue of day-to-day performance is not material. The focus is on
achieving a good return on investment over an extended horizon.
Market risk is managed with a short-term focus. Long-term
losses are avoided by avoiding losses from one day to the next. On a
tactical level, traders and portfolio managers employ a variety of
risk metrics —duration
and convexity, the Greeks,
beta, etc.—to assess their exposures.
These allow them to identify and reduce any exposures they might consider
excessive. On a more strategic level, organizations manage market risk by
applying risk limits to traders'
or portfolio managers' activities. Increasingly,
value-at-risk is being used to
define and monitor these limits. Some organizations also apply
stress testing to
their portfolios.
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beta—a
metric of the systematic risk of a portfolio.
credit risk
Risk that a counterparty may be unable to perform on an
obligation.
duration and
convexity Factor sensitivities employed in fixed income
markets.
financial
risk management Practices by which a firm optimizes the
manner in which it takes financial risk.
Greeks A set of
factor sensitivities used to measure risk exposures related to
options or other derivatives.
Interest rate risk
Risk due to uncertain future interest rates.
legal risk
Risk from uncertainty due to legal actions or uncertainty in the applicability
or interpretation of contracts, laws or regulations.
liquidity risk
Risk due to uncertain liquidity.
operational
risk Risk due to human error, systems failure or external
events.
risk Comprises two components:
uncertainty and exposure.
risk limit
A limit placed upon risk taking activity for the purpose of
avoiding excessive risk.
risk management Practices by which a firm optimizes the
manner in which it takes financial risk.
stress
testing A simple form of scenario analysis typically used to
assess market risk.
valuation
Article about book value and market value accounting.
value-at-risk A
category of market risk measures. |
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Ads by Contingency Analysis
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Allen (2003)
is an excellent book on market risk management in trading
organizations. Butler (1999)
is an elementary text on value-at-risk, Holton (2003)
is a sophisticated book on the same topic.
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