The Omega Point application provides portfolio analysis tools that include describing how a portfolio's factor risk & factor exposure have deviated from their historic values. This is described as a factor's drift and can be found in the right-hand column when using the Analyze: Risk and the Analyze: Exposure modules
Drift is categorized by the following percentile buckets:
Very High
: 95% - 100%
High
: 75% - 95%
Neutral
: 25% - 75%
Low
: 5% - 25%
Very Low
: 0% - 5%
Drift is calculated for the specified date range
— when the date range value is less than 3 months, the app automatically uses as many dates as possible to get a statistically significant drift calculation.Selecting a factor category will display historical factor exposure values [or a factor's risk decomposition values, when using Analyze: Risk].
Dynamically interact with the graph, and introspect any particular date (dashed line), then...
Display that date's weighted-average factor exposures in the right-hand column, and it's drift (red, blue arrows).
Drift Methodology
Find the mean and calculate the standard deviation over the full date range*
Find the difference from today's value from the mean, divided by the standard deviation
driftValue = (todaysValue - mean) / deviation
The driftValue is then bucketed into it's respective percentile by the following categories
driftValue < -1.645σ = Very Low
driftValue < -0.674σ = Low
driftValue < 0.674σ = Neutral
driftValue < 1.645σ = High
driftValue > 1.645σ = Very High
The range [-0.674σ, 0.674σ] represents the range of z-scores that can be mapped for the middle 50% of any set, i.e.
Neutral
: 25% - 75%
The range [0.674σ, 1.645σ] & [-0.674σ, -1.645σ] corresponds to the next 20% of values falling into their respective buckets
High
: 75% - 95%
Low
: 5% - 25%
And values that fall above or below +/- 1.645σ correspond to the last 5% of values
Very High
: 95% - 100%
Very Low
: 0% - 5%