Well, it is not just the CDS ban, the fact that Greece is now done is also a modest factor, but since nobody can short Greek default risk unhedged, the only option is to short the bonds. As they did today en masse. Greek 1 Year bonds: the most liquid proxy for default in the absence of 1 Year CDS, closed at 183%, after hitting an all time high of 188%, following yesterday's 173% close. To all those who bought 1 Year Greek bonds when yields hit 100% a month ago because "they just couldn't possibly drop any more, and you would double your money in one year guaranteed", condolences for the 50% loss. We are certain that a new batch of bottom callers will emerge, this time calling for doubling your money in six months.... Then three.. Then one and a half... etc... Until finally Zeno's paradox catches up and you either double your money overnight or you lose it all.