At the moment, all of the biggest bets are easily accomodated by a much smaller bankroll. This means whatever part of the bankroll isn't being utilized ($60M or so) is a pointless liability. This is why he's incentivizing people to divest, so that the bankroll reaches a more reasonable size - that is, one that is big enough to accomodate massive bets, but doesn't have a huge needless liability attached to securing it.