The term 'alpha' is used to describe the entire algorithm. Therefore, 'alpha'
produces insights. From this we have things like IAlphaModel, which is the model
defining how insights are produced. We have IAlphaHandler, which defines how the
insights from a single 'alpha' (the algorithm) are managed, analyzed, and stored.
Types closer to the individual prediction level, such as InsightDirection, or
InsightScore relate directly to exactly 1 insight. The distinction between the
two became more clear as we developed the insights API, and from that effort it
was decided to harmonize alpha/insight terminology across the various QC systems.
The IAlphaManagerExtension defines a type that needs to react to events produced
by the AlphaManager. The actual events were removed in favor of a interface to
handle the events. This removes the need to wire events and instead just pass the
extensions to the alph manager and it will handle invoking the extensions at the
appropriate time.
This change removes all charting and statistics aggregation logic from the alpha
handler and moves it into dedicated types, AlphaChartingManagerExtension and
AlphaStatisticsManagerExtension. The resulting types are highly decoupled from the
LEAN ecosystem allowing them to be easily unit tested, whereas before the logic
was embedded in a handler with many many dependencies which would be very hard to
properly unit test.
As part of this change (and in preparation for moving scoring to the alpha thread)
the resolution of SecurityValues was removed from the alpha manager. In this new
pattern, the alpha manager is pushed generated alphas and security values at each
time step.
If we make a prediction for 1 day in the future, we actually mean 1 trading day.
This change updates the alpha analysis logic to take into account the security's
market hours.
Michael Handschuh