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Morningstar Quicktake Report: Mutual Fund Data Definitions
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Ratings and Risk
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Morningstar
Ratings
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Morningstar Star Rating
The Morningstar Risk-Adjusted
Rating, commonly called the star rating, brings both performance and risk
together into one evaluation. To determine a fund's star rating for a
given period (three, five, or 10 years), the fund's Morningstar Risk score
is subtracted from its Morningstar Return score. The resulting number
is plotted along a bell curve to determine the fund's rating for each
time period: If the fund scores in the top 10% of its broad investment
class (domestic stock, international stock, taxable bond, or municipal
bond), it receives 5 stars (Highest); if it falls in the next 22.5%, it
receives 4 stars (Above Average); a place in the middle 35% earns it 3
stars (Average); those in the next 22.5% receive 2 stars (Below Average);
and the bottom 10% get 1 star (Lowest). The star ratings are recalculated
monthly.
Morningstar Risk
The Morningstar Risk statistic evaluates the fund's downside volatility
relative to that of other funds in its broad investment class (domestic
stock, international stock, taxable bond, or municipal bond). Morningstar
uses a proprietary risk measure that operates differently from traditional
risk measures, such as beta and standard deviation, which see both greater-
and less-than-expected returns as added volatility. Morningstar believes
that most investors' greatest fear is losing money--defined as underperforming
the risk-free rate of return an investor can earn from the 90-day Treasury
bill--so our risk measure focuses only on that downside risk. To calculate
the risk score, we plot monthly fund returns in relation to T-bill returns.
We add up the amounts by which the fund trails the T-bill return each
month and divide that total by the period's total number of months. This
number, the average monthly underperformance statistic, is then compared
with those of other funds in the same broad investment class to assign
our risk scores. The resulting risk score expresses how risky the fund
is relative to the average fund in its class. The average risk score for
the category is set equal to 1.00; a Morningstar Risk score of 1.35 for
a taxable-bond fund means that the fund has been 35% riskier than the
average taxable-bond fund for the period considered. Note that Morningstar
does not rate any fund that has less than three years of performance data.
Morningstar Return
The Morningstar Return figure rates a fund's performance relative to other
funds in its broad investment class (domestic stock, international stock,
taxable bond, or municipal bond). After adjusting for maximum front-end
loads, applicable deferred loads, and applicable redemption fees, Morningstar
calculates the excess return for each fund, defined as the fund's load-adjusted
return minus the return of the 90-day T-bill over the same period. The
use of excess instead of raw returns reflects our belief that mutual funds
should be rated highly for only those returns earned beyond those of a
T-bill, which is essentially a risk-free investment. The excess returns
are then compared with the higher of the average excess return of the
fund's broad investment class or the 90-day T-bill return. This last adjustment
prevents distortions caused by having low or negative average excess returns
in the equation's denominator, as might occur during a protracted down
market. The equation is: (Return on Fund* - T-bill)/Higher of (Category
Return* - T-bill) or T-bill
* Fund returns are adjusted for loads. Class average is based on load-adjusted
returns. The resulting Morningstar Return figure is listed relative to
the average excess return of the investment class or the T-bill, whichever
is higher. A footnote indicates when the T-bill comparison is used. If
the Morningstar Return figure is compared to the broad investment class,
1.00 represents the class average. Thus, a figure of 1.10 means that the
fund outperformed the class average by 10 percent, while 0.90 means that
the fund underperformed by 10 percent. For T-bill comparisons, the same
concept is true, but 1.00 occurs when a fund's load-adjusted excess return
equals the T-bill. Therefore, a score of 0.90 with a T-bill footnote indicates
that the fund's excess return has been 10% lower than the T-bill. In periods
of low returns, a fund's raw returns could hypothetically underperform
T-bill returns, in which case the figure would be a negative number, such
as minus 0.35, meaning that fund's raw returns were 35% less than those
of the T-bill.
Category Rating
Like the star rating, the Morningstar category rating is a quantitative
measure of risk-adjusted returns. This three-year rating shows how well
a fund has balanced risk and return relative to other funds in the same
Morningstar category. The rating uses the same methodology as the star
rating. Unlike the star rating, however, the category rating does not
reflect any front- or back-end loads. Other expenses, such as 12b-1 fees,
are included. As with the star rating, 5 is the best rating and 1 is the
worst.
Category Return
A statistic that compares a fund's excess return over the risk-free rate
(as measured by the return on Treasury bills) to the average excess return
for the Morningstar category. With the return on Treasury bills set as
the benchmark, the bottom 10% of funds in each Morningstar category earn
a Low category return, 22.5% Below Average, 35% Average, 22.5% Above Average,
and 10% High. If the average excess return of the category is below the
return of the T-bill, the return of T-bill alone is used as the benchmark.
Unlike the familiar Morningstar Return statistic, loads are not accounted
for in category return. Category return is calculated only for a three-year
period.
Category Risk
A statistic that evaluates a fund's downside volatility relative to the
other funds in its Morningstar category. To calculate risk, Morningstar
concentrates on those months during which the fund underperformed the
average return of a three-month Treasury bill. We add up the amounts by
which the fund fell short of the Treasury bill's return and divide the
result by the total number of months in the rating period. The fund's
average monthly loss is then compared with the average monthly loss for
the fund's Morningstar category. The resulting risk rating expresses how
risky the fund is relative to the average fund in its Morningstar category.
The 10% of funds with the least risk in each Morningstar category earn
a Low category risk score, 22.5% earn Below Average, 35% Average, 22.5%
Above Average, and 10% High. Unlike the Morningstar Risk statistic, category
risk is calculated only for a three-year period.
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Volatility
Measurements
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Standard Deviation
Standard deviation is a statistical measure of the range of a fund's performance.
When a fund has a high standard deviation, its range of performance has
been very wide, indicating that there is a greater potential for volatility.
The standard deviation figure provided here is an annualized statistic
based on 36 monthly returns. By definition, approximately 68% of the time,
the total returns of any given fund are expected to differ from its mean
total return by no more than plus or minus the standard deviation figure.
Ninety-five percent of the time, a fund's total returns should be within
a range of plus or minus two times the standard deviation from its mean.
These ranges assume that a fund's returns fall in a typical bell-shaped
distribution.
In any case, the greater the standard deviation, the greater the fund's
volatility. For example, an investor can compare two funds with the same
average monthly return of 5%, but with different standard deviations.
The first fund has a standard deviation of 2.0, which means that its range
of returns for the past 36 months has typically remained between 1% and
9%. On the other hand, assume that the second fund has a standard deviation
of 4.0 for the same period. This higher deviation indicates that this
fund has experienced returns fluctuating between minus 3% and 13%. With
the second fund, an investor might expect greater volatility.
Mean
The mean represents the annualized average monthly return from which the
standard deviation is calculated. The mean will not be exactly the same
as the annualized trailing, three-year return figure for the same year.
(Technically, the mean is an annualized arithmetic average while the total
return figure is an annualized geometric average.)
Sharpe Ratio
Our Sharpe ratio is based on a risk-adjusted measure developed by Nobel
Laureate William Sharpe. It is calculated using standard deviation and
excess return to determine reward per unit of risk. First, the average
monthly return of the 90-day Treasury bill (over a 36-month period) is
subtracted from the fund's average monthly return. The difference in total
return represents the fund's excess return beyond that of the 90-day Treasury
bill, a risk-free investment. An arithmetic annualized excess return is
then calculated by multiplying this monthly return by 12. To show a relationship
between excess return and risk, this number is then divided by the standard
deviation of the fund's annualized excess returns. The higher the Sharpe
ratio, the better the fund's historical risk-adjusted performance.
Bear Market Decile Rank
This statistic enables investors to gauge a fund's performance during
a bear market. As a standard measure, Morningstar compares all equity
funds against the S&P 500 index and all fixed-income funds against
the Lehman Brothers Aggregate Index . We add together a fund's performance
during each bear-market month over the past five years to reach a cumulative
bear-market return. Based on these returns, equity funds are compared
with other equity funds and bond funds are compared with other bond funds.
They are then assigned a decile ranking where the 10% of funds with the
worst performance receive a ranking of 10, and the 10% of funds with the
best performance receive a ranking of 1. Because Morningstar employs the
trailing five-year time period for this statistic, only funds with five
years of history are given a bear-market decile ranking.
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 Modern
Portfolio Theory Statistics |
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R-Squared vs. Standard Index
R-squared ranges from 0 to 100 and reflects the percentage of a fund's
movements that are explained by movements in its benchmark index. An R-squared
of 100 means that all movements of a fund are completely explained by
movements in the index. Thus, index funds that invest only in S&P
500 stocks will have an R-squared very close to 100. Conversely, a low
R-squared indicates that very few of the fund's movements are explained
by movements in its benchmark index. An R-squared measure of 35, for example,
means that only 35% of the fund's movements can be explained by movements
in its benchmark index. Therefore, R-squared can be used to ascertain
the significance of a particular beta or alpha. Generally, a higher R-squared
will indicate a more useful beta figure. If the R-squared is lower, then
the beta is less relevant to the fund's performance.
Beta vs. Standard Index
Beta, a component of Modern Portfolio Theory statistics, is a measure
of a fund's sensitivity to market movements. It measures the relationship
between a fund's excess return over T-bills and the excess return of the
benchmark index. Equity funds are compared with the S&P 500 index;
bond funds are compared with the Lehman Brothers Aggregate Bond index.
Morningstar calculates beta using the same regression equation as the
one used for alpha, which regresses excess return for the fund against
excess return for the index. This approach differs slightly from other
methodologies that rely on a regression of raw returns.
By definition, the beta of the benchmark (in this case, an index) is
1.00. Accordingly, a fund with a 1.10 beta has performed 10% better than
its benchmark index--after deducting the T-bill rate--than the index in
up markets and 10% worse in down markets, assuming all other factors remain
constant. Conversely, a beta of 0.85 indicates that the fund has performed
15% worse than the index in up markets and 15% better in down markets.
A low beta does not imply that the fund has a low level of volatility,
though; rather, a low beta means only that the funds market-related risk
is low. A specialty fund that invests primarily in gold, for example,
will often have a low beta (and a low R-squared), relative to the S&P
500 index, as its performance is tied more closely to the price of gold
and gold-mining stocks than to the overall stock market. Thus, though
the specialty fund might fluctuate wildly because of rapid changes in
gold prices, its beta relative to the S&P may remain low.
Alpha vs. Standard Index
Alpha measures the difference between a fund's actual returns and its
expected performance, given its level of risk (as measured by beta). A
positive alpha figure indicates the fund has performed better than its
beta would predict. In contrast, a negative alpha indicates a fund has
underperformed, given the expectations established by the fund's beta.
Some investors see alpha as a measurement of the value added or subtracted
by a fund's manager. There are limitations to alpha's ability to accurately
depict a manager's added or subtracted value. In some cases, a negative
alpha can result from the expenses that are present in the fund figures
but are not present in the figures of the comparison index. Alpha is dependent
on the accuracy of beta: If the investor accepts beta as a conclusive
definition of risk, a positive alpha would be a conclusive indicator of
good fund performance. Of course, the value of beta is dependent on another
statistic, known as R-squared. (Alpha, beta, and R-squared statistics
are all provided on Morningstar.com.)
For Alpha vs. the Standard Index, Morningstar performs its calculations
using the S&P 500 as the benchmark index for equity funds and the
Lehman Brothers Aggregate as the benchmark index for bond funds. Morningstar
deducts the current return of the 90-day T-bill from the total return
of both the fund and the benchmark index. The difference is called the
fund's excess return. The exact mathematical definition of alpha that
Morningstar uses is listed below.
Alpha = Excess Return - ((Beta x (Benchmark - Treasury))
Benchmark = Total Return of Benchmark Index
Treasury = Return on Three-month Treasury Bill
R-Squared vs. Best-fit Index
R-squared ranges from 0 to 100 and reflects the percentage of a fund's
movements that are explained by movements in its benchmark index.
An R-squared of 100 means that all movements of a fund are completely
explained by movements in the index. In this instance, the benchmark index
is the best-fit index. To obtain the best-fit index, Morningstar regresses
the fund's monthly excess returns against monthly excess returns of several
well-known market indexes. Best fit signifies the index that provides
the highest R-squared.
Beta vs. Best-fit Index
Beta, a component of Modern Portfolio Theory statistics, is a measure
of a fund's sensitivity to market movements. It measures the relationship
between a fund's excess return over T-bills and the excess return of the
best-fit index. For Beta
vs. the Best-Fit Index, Morningstar first determines the fund’s best-fit
index. Morningstar regresses the fund’s monthly excess returns against
monthly excess returns of several well-known market indexes. Best fit
signifies the index that provided the highest R-squared when the fund
was regressed against it.
By definition, the beta of
the benchmark (in this case, an index) is 1.00. Accordingly, a fund with
a 1.10 beta has performed 10% better than its benchmark index--after deducting
the T-bill rate--than the index in up markets and 10% worse in down markets,
assuming all other factors remain constant. Conversely, a beta of 0.85
indicates that the fund has performed 15% worse than the index in up markets
and 15% better in down markets. A low beta does not imply that the fund
has a low level of volatility, though; rather, a low beta means only that
the funds market-related risk is low.
Alpha vs. Best Fit Index
Alpha measures the difference between a fund's actual returns and its
expected performance, given its level of risk (as measured by beta).
A positive alpha figure indicates the fund has performed better than its
beta would predict. In contrast, a negative alpha indicates a fund has
underperformed, given the expectations established by the fund's beta.
Some investors see alpha as a measurement of the value added or subtracted
by a fund's manager. There are limitations to alpha's ability to accurately
depict a manager's added or subtracted value. In some cases, a negative
alpha can result from the expenses that are present in the fund figures
but are not present in the figures of the comparison index. Alpha is dependent
on the accuracy of beta: If the investor accepts beta as a conclusive
definition of risk, a positive alpha would be a conclusive indicator of
good fund performance. Of course, the value of beta is dependent on another
statistic, known as R-squared. (Alpha, beta, and R-squared statistics
are all provided on Morningstar.com.)
For Alpha vs. the Best-Fit Index, Morningstar first determines the fund’s
best-fit index. Morningstar regresses the fund’s monthly excess returns
against monthly excess returns of several well-known market indexes. Best
fit signifies the index that provided the highest R-squared when the fund
was regressed against it. After determining the best-fit index, Morningstar
deducts the current return of the 90-day T-bill from the total return
of both the fund and the best-fit index. The difference is called the
fund's excess return. The exact mathematical definition of alpha that
Morningstar uses is listed below.
Alpha = Excess Return - ((Beta
x (Benchmark - Treasury))
Benchmark = Total Return of Benchmark Index
Treasury = Return on Three-month Treasury Bill
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Copyright 2000 Morningstar, Inc. All rights reserved.
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