KCG is toast. They have no friends which is why JPM and others refused to extend them stabilization loans.
KCG likely will be taken over and stabilized by one or more financial houses. My guess would be this happens without a Chapter 11 filing.
... Then the sheep broke out into a tremendous bleating of "Four legs good, two legs bad!" which went on for nearly a quarter of an hour and put an end to any chance of discussion. George Orwell, Animal Farm