Serious doubts remain about the effectiveness of value at risk or VAR quant models used by JP Morgan Chase to measure potential losses on a trade on a bad day. A newer model used by Chase in the first quarter showed smaller losses. When the old model was run this trade showed double the losses according to Chase managers. Greenberger, a former CFTC official and a professor at the University of Maryland School of Law, says if the trade become hard to unwind it shows poor risk management. And experts say it is not much of a hedge if it is done in an obscure part of credit markets and hard to unwind without serious losses. Peter Tchir, a former head of index trading at RBS bank, says CEO Dimon must have seen these kinds of hedges as part of his overall strategy, which is why he supported them in April 2012. The problem lies in that the bank size has grown to such proportions that its simply too big to manage, with trades it has to make becoming massive as a consequence.