CalmarRatio: calculate a Calmar or Sterling reward/risk ratio
Calmar and Sterling Ratios are yet another method of creating a
risk-adjusted measure for ranking investments similar to the
SharpeRatio.
Description
Both the Calmar and the Sterling ratio are the ratio of annualized return
over the absolute value of the maximum drawdown of an investment. The
Sterling ratio adds an excess risk measure to the maximum drawdown,
traditionally and defaulting to 10%.
Usage
CalmarRatio(R, scale = NA)
SterlingRatio(R, scale = NA, excess = 0.1)
Arguments
R
an xts, vector, matrix, data frame, timeSeries or zoo object of
asset returns
scale
number of periods in a year (daily scale = 252, monthly scale =
12, quarterly scale = 4)
excess
for Sterling Ratio, excess amount to add to the max drawdown,
traditionally and default .1 (10%)
Author
Brian G. Peterson
Details
It is also traditional to use a three year return series for these
calculations, although the functions included here make no effort to
determine the length of your series. If you want to use a subset of your
series, you'll need to truncate or subset the input data to the desired
length.
Many other measures have been proposed to do similar reward to risk ranking.
It is the opinion of this author that newer measures such as Sortino's
UpsidePotentialRatio or Favre's modified
SharpeRatio are both “better” measures, and
should be preferred to the Calmar or Sterling Ratio.
References
Bacon, Carl. Practical Portfolio Performance Measurement
and Attribution. Wiley. 2004.