Anyone looking at a heatmap of European markets today will see a sea of green punctuated by a very red island in the middle. The culprit: Austrian mega bank Erste, which issued an ad hoc and very unexpected press release, in which it warned that losses in its Hungarian and Romanian books would lead to a 14% hit, or €1.1 billion, to tangible book value, something that in itself is not a surprise to anyone (except the stress test). After all, since early 2010, most have known that due to Swiss Franc-based mortgage exposure, Hungary is next to follow in the PIIGS footsteps, and its collapse has so far been delayed due to lower overall public and private sector leverage. What was, however not only a surprise, but a shock, was that Erste disclosed some major losses on its €5.2 billion CDS portfolio, consisting of "EUR 2.4 billion related to financial institution exposures, and EUR 2.8 billion related sovereign exposures". Why is this a surprise? UK-based financial advisory Autonomous explains: "The fact that Erste had a sovereign CDS portfolio which was not marked-to-market has left many investors scratching their heads. As a reminder the EBA stress test data showed Erste to have zero sovereign CDS exposure within its sovereign mix compared to the €2.8bn it now appears to have ‘fessed up’ to (taking a cumulative €460m hit). They also have €2.4bn exposure to banks via writing of CDS. The bulk is non-PIIGS but banks spreads have moved in the same manner as sovereigns (albeit wider and more volatile)." And there you have it: the bogeyman that everyone has been warning about, yet nobody has seen, CDS written (as in sold) in bulk against other sovereigns and other banks which up until now were only mythical, as they, to quote the EBA (which had Dexia as its safest bank) simply did not exist. Oh, they exist all right, and what they do is create a toxic spiral of accentuating losses whenever the risk situation deteriorates, creating positive feedback loops of ever increasing losses until the next Dexia appears... and then the next... and the next. Expect the market to latch on to this dramatic revelation like a rabid pitbull once the hopium high from today's EURUSD short covering squeeze wears off.