“Synthetic credit portfolio”. That’s the book where the $2bn in mark-to-market losses took place for JP Morgan, according to an announcement made on Thursday. A result which has now cost them a their AA- rating from Fitch and landed them on negative outlook with S&P, as announced late on Friday.

FT Alphaville has analysed the credit trades that might be in that portfolio, in an attempt to reason through what may have gone on. The fact, however, remains that we know precious little. Why is that? Is this acceptable that after the financial crisis that this can happen to a bank, let alone a systemically important one like JP Morgan? Read more