where µd
represents the daily return of the strategy over the
past three months, σd
represents the standard deviation of daily
returns over the last three months, and T represents the number
of trading days that Amaranth used for VaR (i.e. 20 days).
The confidence levels were chosen to conform closely with
the risk reports that Amaranth produced internally on a daily
basis (see Section II).
for September on August 31, 2006 is then computed as follows