Goldman cannot separate Derivative Profits

from its profits in cash securities. According to Bloomberg Goldman Sachs has refused to disclose how much it makes trading derivatives to the Financial Crisis Inquiry Commission. Goldman CFO David Viniar stated that the firm 'has no way of separating out its derivatives data from trading in cash securities'.
We can only assume that some information got lost on the way from the FCIC to the reporter as we can not imagine that at a time when computing power is so abundant it would not be possible to separate the profitability by product - down to the P&L of each individual transaction.