Value
Added Monthly Index (VAMI) - This index reflects the growth of a
hypothetical $1,000 in a given investment over time. The index is equal to $1,000 at inception. Subsequent month-end values are calculated
by multiplying the previous month’s VAMI index by 1 plus the current month rate
of return.
Where Vami 0 = 1000 and
Where R N = Return for period N
Vami N
= ( 1 + R N )
´ Vami N-1
Average
Return (Mean) - This is a simple average return (arithmetic mean)
which is calculated by summing the returns for each period and dividing the
total by the number of periods. The
simple average does not take the compounding effect of investment returns into
account.
Where N = Number of periods
Where R I = Return for period I
N
Average
Return = ( S R I ) ¸ N
I=1
Average
Gain (Gain Mean) - This is a simple average (arithmetic mean) of the
periods with a gain. It is calculated
by summing the returns for gain periods (return ³ 0) and then dividing the
total by the number of gain periods.
Where N = Number of periods
Where R I = Return for period I
Where G I = R I ( IF R I ³ 0 ) or 0 ( IF R I < 0 )
N G = Number of periods that R I ³ 0
N
Average Gain = ( S G I ) ¸ N
G
I=1
Average
Loss (Loss Mean) - This is a simple average (arithmetic mean) of the
periods with a loss. It is calculated
by summing the returns for loss periods (return < 0) and then dividing
the total by the number of loss periods.
Where N = Number of periods
Where R I = Return for period I
Where L I = 0 ( IF R I ³ 0 ) or R I ( IF R I < 0 )
N L = Number of periods that R I < 0
N
Average Loss = ( S L I ) ¸ N L
I=1
Compound
(Geometric) Average Return - The geometric mean is the monthly
average return that assumes the same rate of return every period to arrive at
the equivalent compound growth rate reflected in the actual return data. In other words, the geometric mean is the
monthly average return that, if applied each period, would give you a final
Vami (growth) index that is equivalent to the actual final Vami index for the
return stream you are considering. In
PerTrac 2000, compound quarterly and annualized returns are calculated using
the compound monthly return as a base.
Where N = Number of periods
Where Vami (0)
= 1000
Compound Monthly ROR = ( Vami N ¸ Vami 0 ) 1/ N - 1
Compound Quarterly ROR = ( 1 + Compound Monthly ROR ) 3 - 1
Compound Annualized ROR = ( 1 + Compound Monthly ROR ) 12 - 1
Standard
Deviation - Standard Deviation measures the dispersal or uncertainty
in a random variable (in this case, investment returns). It measures the degree of variation of
returns around the mean (average) return.
The higher the volatility of the investment returns, the higher the
standard deviation will be. For this
reason, standard deviation is often used as a measure of investment risk.
Where R I = Return for period I
Where M R = Mean of return set R
Where N = Number of Periods
N
M R = ( S R I ) ¸ N
I=1
N
Standard Deviation = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½
I = 1
Annualized Standard Deviation
Annualized Standard Deviation = Monthly Standard Deviation ´ ( 12 ) ½
Annualized Standard
Deviation * = Quarterly Standard
Deviation ´
( 4 ) ½
* Quarterly Data
Gain
Standard Deviation - Similar to standard deviation, except this
statistic calculates an average (mean) return for only the periods with a gain and then measures the variation of
only the gain periods around this
gain mean. This statistic measures the
volatility of upside performance.
Where N = Number of Periods
Where R I = Return for period I
Where M G = Gain Mean
Where G I = R I ( IF R I ³ 0 ) or 0 ( IF R I < 0 )
Where GG I = R I - M G ( IF R I ³ 0 ) or 0 ( IF R I < 0 )
N G = Number of periods that R I ³ 0
N
M G = ( S G I ) ¸ N
G
I=1
N
Gain Deviation = ( S (GG I ) 2 ¸ (N G - 1) ) ½
I=1
Loss
Standard Deviation - Similar to standard deviation, except this
statistic calculates an average (mean) return for only the periods with a loss and then measures the variation of
only the losing periods around this
loss mean. This statistic measures the volatility of downside performance.
Where N = Number of Periods
Where R I = Return for period I
Where M L = Loss Mean
Where L I = R I ( IF R I < 0 )or 0 ( IF R I ³ 0 )
Where LL I = R I - M L ( IF R I < 0 ) or 0 ( IF R I ³ 0 )
N L = Number of periods that R I < 0
N
M L = ( S L I ) ¸ N
L
I=1
N
Loss Deviation = ( S ( LL I) 2 ¸ (N L - 1) ) ½
I=1
Downside
Deviation - Similar to the loss
standard deviation except the downside deviation considers only returns that
fall below a defined Minimum Acceptable Return (MAR) rather then the arithmetic
mean. For example, if the MAR is
assumed to be 10%, the downside deviation would measure the variation of each
period that falls below 10%. (The loss standard deviation, on the other hand,
would take only losing periods, calculate an average return for the losing periods, and then measure the
variation between each losing return and the losing return average). In PerTrac 2000,
there are 3 downside deviation calculations, each using a different value for
the MAR: 1)Uses a MAR which is defined by the user on the Preferences screen, 2) Uses the Sharpe risk free rate (which can
also be defined in Preferences) as
the MAR, and 3) uses zero as the MAR.
Where R I = Return for period I
Where N = Number of Periods
Where R MAR = Period Minimum Acceptable Return
Where L I = R I - R MAR ( IF R I - R MAR < 0 )or 0 ( IF R I - R MAR ³ 0 )
N
Downside Deviation = ( (S ( L I ) 2 ) ¸ N ) ½
I=1
Semi
Deviation
Where R I = Return for period I
Where N = Number of Periods
Where M = Period Arithmetic Mean
Where L I = R I - M ( IF R I - M < 0 )or 0 ( IF R I - M ³ 0 )
Where NL = Number of Periods where R I - M < 0
N
Semi Deviation = ( (S ( L I ) 2 ) ¸ (NL
-1)) ½
I=1
Sharpe
Ratio - A return/risk measure developed by William Sharpe. Return (numerator) is defined as the
incremental average return of an investment over the risk free rate. Risk (denominator) is defined as the
standard deviation of the investment returns.
In PerTrac 2000, the user enters the value for the risk free rate.
Where R I = Return for period I
Where M R = Mean of return set R
Where N = Number of Periods
Where SD = Period Standard Deviation
Where R RF = Period Risk Free Return
N
M R = ( S R I ) ¸ N
I=1
N
SD = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½
I = 1
Sharpe Ratio = ( M R - R RF ) ¸ SD
Annualized Sharpe Ratio
Annualized Sharpe = Monthly Sharpe ´ ( 12 ) ½
Annualized Sharpe * = Quarterly Sharpe ´ ( 4 ) ½ * Quarterly Data
Sortino Ratio - This is another return/risk ratio developed by Frank Sortino. Return (numerator) is defined as the incremental compound average period return over a Minimum Acceptable Return (MAR). Risk (denominator) is defined as the Downside Deviation below a Minimum Acceptable Return (MAR). Just as with the Downside Deviation calculation, PerTrac 2000 calculates the Sortino using 3 different values for the MAR: 1) a MAR defined by the user under Preferences, 2) the Sharpe ratio risk free rate (also set under Preferences), and 3) zero.
Where R I = Return for period I
Where N = Number of Periods
Where R MAR = Period Minimum Acceptable Return
Where DD MAR = Downside Deviation
Where L I = R I - R MAR ( IF R I - R MAR < 0 )or 0 ( IF R I - R MAR ³ 0 )
N
DD MAR = ( (S ( L I ) 2
) ¸ N ) ½
I=1
Sortino Ratio = ( Compound Period Return - R MAR ) ¸ DD MAR
Annualized Sortino Ratio
Annualized Sortino = Monthly Sortino ´ ( 12 ) ½
Annualized
Sortino* = Quarterly Sortino ´ ( 4
) ½
* Quarterly Data
Skewness - Skewness characterizes the degree of asymmetry of a distribution around its mean. Positive skewness indicates a distribution with an asymmetric tail extending toward more positive values. Negative skewness indicates a distribution with an asymmetric tail extending toward more negative values.
Where N = Number of Periods
Where R I = Return for period I
Where M R = Mean of return set R
Where SD = Period Standard Deviation
N
M R = ( S R I ) ¸ N
I=1
N
SD = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½
I = 1
N
Skewness = ( N ¸ ((N-1)(N-2)) ) ( S (R I – M R) ¸ SD) ) 3
I =
1
If there are fewer than three data points, or the sample standard deviation is zero, Skewness returns the N/A error value.
Kurtosis - Kurtosis characterizes the relative peakedness or flatness of a distribution compared with the normal distribution. Positive kurtosis indicates a relatively peaked distribution. Negative kurtosis indicates a relatively flat distribution.
Where N = Number of Periods
Where R I = Return for period I
Where M R = Mean of return set R
Where SD = Period Standard Deviation
N
M R = ( S R I ) ¸ N
I=1
N
SD = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½
I = 1
N
Kurtosis = {(N(N+1) ¸ ((N-1)(N-2)(N-3))) (S (R I – M R) ¸ SD))4} - (3(N-1)2 ¸ ((N-2)(N-3)))
I = 1
If there are fewer than
four data points, or if the standard deviation of the sample equals zero,
Kurtosis returns the N/A error value.
Calmar Ratio - This is a return/risk ratio. Return (numerator) is defined as the Compound Annualized Rate of Return over the last 3 years. Risk (denominator) is defined as the Maximum Drawdown over the last 3 years. If three years of data are not available, the available data is used. ABS is the Absolute Value.
Calmar Ratio = Compound Annualized ROR ¸ ABS (Maximum Drawdown )
Sterling Ratio - This is a return/risk ratio. Return (numerator) is defined as the Compound Annualized Rate of Return over the last 3 years. Risk (denominator) is defined as the Average Yearly Maximum Drawdown over the last 3 years less an arbitrary 10%. To calculate this average yearly drawdown, the latest 3 years (36 months) is divided into 3 separate 12-month periods and the maximum drawdown is calculated for each. Then these 3 drawdowns are averaged to produce the Average Yearly Maximum Drawdown for the 3 year period. If three years of data are not available, the available data is used.
Where D1 = Maximum Drawdown for first 12 months
Where D2 = Maximum Drawdown for next 12 months
Where D3 = Maximum Drawdown for latest 12 months
Average Drawdown = ( D1 + D2 + D3 ) ¸ 3
Sterling Ratio = Compound Annualized ROR ¸ ABS ( (Average Drawdown - 10% ))
Drawdown - A Drawdown is any losing period during an investment record. It is defined as the percent retrenchment from an equity peak to an equity valley. A Drawdown is in effect from the time an equity retrenchment begins until a new equity high is reached. (i.e. In terms of time, a drawdown encompasses both the period from equity peak to equity valley (Length) and the time from the equity valley to a new equity high (Recovery).
Maximum Drawdown is simply the largest percentage drawdown that has occurred in any investment data record.
The Drawdown Table in PerTrac 2000 provides a comprehensive
list of all drawdowns in the historical performance record ranked from largest
to smallest.
Gain
to Loss Ratio - This is a
simple ratio of the average gain in a gain period divided by the average loss
in a losing period. Periods can be
monthly or quarterly depending on the data frequency.
Gain/Loss Ratio = ABS (Average Gain in Gain Period ¸ Average Loss in Loss Period)
$ Profit to Loss Ratio - This ratio combines the Gain to Loss Ratio with the ratio of the percentage of profitable periods to the percentage of losing periods. Since this ratio considers both the average size and the frequency of winning and losing periods, it tells you the historical ratio of dollars earned in the investment to dollars lost. For example, a $ Profit to Loss Ratio of 2.5 means that, historically, the investment earned $2.50 of profit for each $1.00 of risk taken.
$ Profit/Loss Ratio = (% Profitable Periods ¸ % Losing Periods) ´ Gain to Loss Ratio
Correlation Analysis - All of the following correlation related statistics use the following variables:
Where R I = The return of the independent variable for period I
Where RD I = The return of the dependent variable for period I
Where M R = The mean return of the independent variable
Where M RD = The mean return of the dependent variable
Where N = Number of Periods
Beta - Beta is the slope of the regression line. Beta measures the risk of a particular investment relative to the market as a whole (the “market” can be any index or investment you specify). It describes the sensitivity of the investment to broad market movements. For example, in equities, the stock market (the independent variable) is assigned a beta of 1.0. An investment which has a beta of .5 will tend to participate in broad market moves, but only half as much as the market overall.
N N
Beta = (S (R I - M R
) (RD I - M RD)
) ¸ (S (R I -
M R ) 2 )
I=1 I=1
Alpha - Alpha is a measure of value added. It is the Y intercept of the regression line.
Alpha = M RD - Beta ´ M R
Annualized Alpha – Annualized Alpha is the annualized value of Alpha.
Annualized Alpha = ((1 + Alpha)12 - 1 (Monthly Data)
Annualized Alpha = ((1 + Alpha)4 - 1 (Quarterly Data)
Correlation and Correlation Coefficient - Correlation measures the extent of linear association of two variables. The Coefficient of Determination ( R2 ) is a measure of how well the regression line fits the data (variation explained by the regression line). Unexplained variation is simply 1- R2 .
Correlation Coefficient ( r )
Where S XY = Sample Covariance
Where S X = Standard deviation of independent variable
Where S Y
= Standard deviation of dependent variable
N
S XY = (S (R I -
M R ) (RD I - M RD)
) ¸ (N - 1 ) )
I=1
N
S X = ( S ( R I - M R ) 2 ¸ (N - 1) ) ½
I = 1
N
S Y = ( S ( RD I - M RD ) 2 ¸ (N - 1) ) ½
I = 1
Correlation Coefficient = S XY ¸ (S X ´ S Y )
Coefficient of Determination ( r 2
)
Where Y I = Alpha + Beta ´ R I
N N
Coefficient of Determination = ( S ( Y I - M RD ) 2) ¸ ( S ( RD I - M RD ) 2)
I = 1 I=1
Tracking Error (Annualized) - Tracking Error is a measure of the unexplained portion of an investments performance relative to a benchmark. Annualized Tracking Error is measured by taking the square root of the average of the squared deviations between the investment’s returns and the benchmark’s returns, then multiplying the result by the square root of 12.
N
Tracking Error = ( (
S ( R I - RD I) 2 ¸ (N-1) ) ½) ´ 12½
I = 1
Treynor
Ratio – The Treynor Ratio, developed by Jack Treynor, is similar to
the Sharpe Ratio, except that it uses Beta as the volatility measurement.
Return (numerator) is defined as the incremental average return of an
investment over the risk free rate.
Risk (denominator) is defined as the Beta of the investment returns relative
to a benchmark. In PerTrac 2000, the
user enters the value for the risk free rate.
Where M R = Annualized Return of Investment
Where R RF = Annualized Risk Free Return
Treynor Ratio = ( M R - R RF ) ¸ Beta
Jensen Alpha -
The Jensen Alpha, developed by Michael Jensen, quantifies the extent to which
an investment has added value relative to a benchmark. The Jensen Alpha is
equal to the Investment’s average return in excess of the risk free rate minus
the Beta times the Benchmark’s average return in excess of the risk free rate.
In PerTrac 2000, the user enters the value for the risk free rate.
Where R I = Benchmark Return for period I
Where RD I = Return for period I
Where M R = Mean of return set R (Benchmark)
Where M RD = Mean of return set RD
Where N = Number of Periods
Where R RF = Period Risk Free Return
N
M R = ( S R I ) ¸ N
I=1
N
M RD = ( S RD I ) ¸ N
I=1
Jensen Alpha = ( M RD - R RF ) - Beta ´ ( M R - R RF )
Active Premium - A measure of the Investment’s annualized return minus the Benchmark’s annualized return.
Active Premium = Investment’s annualized return - Benchmark’s annualized return.
Information Ratio - The Information Ratio is the Active Premium divided by the Tracking Error. This measure explicitly relates the degree by which an Investment has beaten the Benchmark to the consistency by which the Investment has beaten the Benchmark.
Information Ratio = Active Premium ¸
Tracking Error
Up Capture - The Up Capture Ratio is a measure of the Investment’s compound return when the Benchmark was up divided by the Benchmark’s compound return when the Benchmark was up. The greater the value, the better.
Where R I = Return for period I
Where RD I = Benchmark Return for period I
Where N = Number of Periods
Where L I = R I (IF RDI ³ 0) or 0 (IF RDI < 0)
Where LDI = RDI (IF RDI ³ 0) or 0 (IF RDI < 0)
T = ((1+L0) ´ (1+L1) ´ … ´ (1+LN)) -1
TD = ((1+LD0) ´ (1+LD1) ´ … ´ (1+LDN)) -1
Up Capture = T ¸ TD
Down Capture - The Down Capture Ratio is a measure of the Investment’s compound return when the Benchmark was down divided by the Benchmark’s compound return when the Benchmark was down. The smaller the value, the better.
Where R I = Return for period I
Where RD I = Benchmark Return for period I
Where N = Number of Periods
Where L I = RI (IF RDI < 0) or 0 (IF RDI ³ 0)
Where LD I = RDI (IF RDI < 0) or 0 (IF RDI ³ 0)
T = ((1+L0) ´ (1+L1) ´ … ´ (1+LN)) -1
TD = ((1+LD0) ´ (1+LD1) ´ … ´ (1+LDN)) -1
Down Capture = T ¸ TD
Up # - The Up Number Ratio is a measure of the number of periods that the Investment was up, when the Benchmark was up, divided by the number of periods that the Benchmark was up. The larger the ratio, the better.
Where RI = Return for period I
Where RDI = Benchmark Return for period I
Where N = Number of Periods
Where LI = 1 (IF RI ³ 0 AND RDI ³ 0) ELSE 0
Where LDI = 1 (IF RDI ³ 0) ELSE 0
N
T = (S
L I)
I=1
N
TD = (S
LD I)
I=1
Up Number Ratio = T ¸ TD
Down # - The Down Number Ratio is a measure of the number of periods that the Investment was down when the Benchmark was down, divided by the number of periods that the Benchmark was down. The smaller the ratio, the better.
Where R I = Return for period I
Where RD I = Benchmark Return for period I
Where N = Number of Periods
Where L I = 1 (IF RI < 0 AND RDI < 0) ELSE 0
Where LD I = 1 (IF RDI < 0) ELSE 0
N
T = (S
L I)
I=1
N
TD = (S
LD I)
I=1
Down Number Ratio = T ¸ TD
Up % - The Up Percentage Ratio is a measure of the number of periods that the Investment outperformed the Benchmark when the Benchmark was up, divided by the number of periods that the benchmark was up. The larger the ratio, the better.
Where RI = Return for period I
Where RDI = Benchmark Return for period I
Where N = Number of Periods
Where LI = 1 (IF RI ³ RDI AND RDI ³ 0) ELSE 0
Where LDI = 1 (IF RDI ³ 0) ELSE 0
N
T = (S
L I)
I=1
N
TD = (S
LD I)
I=1
Up Percentage Ratio = T ¸ TD
Down % - The Down Percentage Ratio is a measure of the number of periods that the Investment outperformed the Benchmark when the Benchmark was down, divided by the number of periods that the benchmark was down. The larger the ratio, the better.
Where RI = Return for period I
Where RDI = Benchmark Return for period I
Where N = Number of Periods
Where LI = 1 (IF RI ³ RDI AND RDI < 0) ELSE 0
Where LDI = 1 (IF RDI < 0) ELSE 0
N
T = (S
L I)
I=1
N
TD = (S
LD I)
I=1
Down Percentage Ratio
= T ¸ TD
% Gain - The Percent Gain Ratio is a measure of the number of periods that the Investment was up divided by the number of periods that the Benchmark was up. The larger the ratio, the better.
Where RI = Return for period I
Where RDI = Benchmark Return for period I
Where N = Number of Periods
Where LI = 1 (IF RI ³ 0) ELSE 0
Where LDI = 1 (IF RDI ³ 0) ELSE 0
N
T = (S
L I)
I=1
N
TD = (S
LD I)
I=1
Percent Gain Ratio = T ¸ TD