  We give an explicit algorithm and source code for extracting equity risk
factors from dead (a.k.a. "flatlined" or "hockey-stick") alphas and using them
to improve performance characteristics of good (tradable) alphas. In a
nutshell, we use dead alphas to extract directions in the space of stock
returns along which there is no money to be made (and/or those bets are too
volatile). In practice the number of dead alphas can be large compared with the
number of underlying stocks and care is required in identifying the aforesaid
directions.
