Milan derivatives fraud trial hinges on banks' sums

For those involved in the case, it came as no surprise when a Milan court decided on March 17 four banks should stand trial over derivatives transactions with the city. The preliminary investigation, which concluded with the judge's ruling, is an attempt to weed out obviously spurious claims, and even those defending the banks involved: Depfa, Deutsche, JP Morgan and UBS, concede there is a debate to be had. What happens next is far harder to predict.

The key question is whether the banks