In a note by JPMorgan's Nikolaos Panigirtzoglou, the strategist warned that, "in our opinion it is not so much funding issues but rather derivatives exposures that more likely to trouble markets going forward if Deutsche Bank concerns continue. This is especially true if these concerns propagate into a confidence crisis inducing more rapid unwinding of derivative contracts."

For those new to the story, Deutsche has one of the world's largest notional derivatives books — its portfolio of financial contracts based on the value of other assets. As we first noted in 2013, It peaked at over $75 trillion, about 20 times German GDP, but had shrunk to around $46 trillion by the end of last year. That's around 12% of the total notional value of derivatives outstanding worldwide ($384 trillion), according to the Bank for International Settlements.  It was €46 trillion as of Q2 measured by notional outstanding.