First the good news for Bill Ackman: as of October 31, it appears that Pershing Square has not had a spike in redemption requests (or if it has, it hasn't granted them yet). We know this because as of October 31, Pershing Square's AUM was $15.1 billion.
This is down from $16.5 billion the month before. This means that the $1.4 billion drop in AUM is largely accounted for by the $75 or so drop in Valeant shares during the month of October (of which Ackman owned about 20 million for most of the month) and that there has been little additional changes to Pershing's portfolio.
The bad news is that at $15.1 billion, this is the lowest AUM for Bill Ackman in over a year...
... and his current net performance for October and YTD is a deplorable -7.3%, and -19.0% respectively.
And yet if this collapse in Pershing's return YTD on the back of just one stock (memories of PS IV and Target come to mind) is enough to lead to the overdue unwinding of his hedge fund, we doubt the billionaire hedge funder will lose much sleep. He is largely set for life.
However, we can't say the same for those unlucky souls who invested in the stock of Dutch-listed stock of Pershing Square hodlings, which recently hit its all time low, and which - if the fund is unwound - will likely proceed to likewise liquidate on short notice.