Don't sell Germany short
Berlin: "Germany's lost the plot: it's rushing ahead on banning speculation, and now it wants other countries to go along."
This has been the widespread reading of what the German regulator did yesterday.
I write this from Berlin, and I can tell you that this summary is completely wrong.
For starters, the German government has not lost the plot - it merely wants to rewrite it to reflect German political realities.
German officials are under no illusions. They know that a unilateral ban on these trades - just in Germany - will not make much difference to anything.
They also know that other countries are unlikely to follow them anytime soon. They are not really asking them to.
I'm sitting in the Finance Ministry, at their G20 conference on reforming financial regulation. The finance minister hosted a dinner last night for the delegates, and I'm told that the German officials present were a bit sheepish about yesterday's ban.
They were also privately furious at Bafin, the German regulator, for allowing news of the ban to leak on Tuesday, before the Germans had been able to brief other governments.
So yes, that part of the German move was cock-up, not conspiracy. Officials had wanted to explain the move in advance.
Germany does want to see longer term reforms in this area - it is pressing the European Commission to put forward a draft directive that would take a serious look at some of these trades.
To be clear, as Robert Peston notes today, naked trading of sovereign credit default swaps doesn't have a lot of fans in official circles right now. Even if no-one thinks they have contributed much to the euro's troubles.
But this move isn't about that kind of longer term reform. It's about getting the 440bn euros special vehicle for supporting eurozone governments through the German parliament.
The key vote happens tomorrow. That is why we are seeing more of Chancellor Merkel today than originally planned. She's giving a last-minute speech to parliament later as well.
As I said on Today this morning, she needs to make this a crisis about "who runs Europe - governments or the markets?" If it is about whether or not to bail out profligate Southern Europeans, she will fail.
So, yes, it might have increased instability in the short run - witness what happened to European stocks yesterday.
But the German government's argument to officials in the US, the UK, and elsewhere has been that this ban will actually be a net positive for the markets - in the end - if it helps Germany get that support package through.
It's a pretty roundabout argument. But who knows? They might be right.
Certainly, investors are going to lose patience with eurozone governments quite soon if they don't get more details on how this massive support programme is going to work.
If this helps that move forward, it will help the eurozone, at least in the short-term.
Tomorrow the European governments - all 27 of them - will start work on the macroeconomic co-ordination side of the package, a discussion which, once again, the Germans plan to dominate.
The UK is not going to get dragged into anything it doesn't want to get into. But we will be there.
Be in no doubt: in return for signing-off on this rescue package, Germany will want the new rules of the road to be written in Germany's own image.
Chancellor Merkel has just alluded to this in her speech here - Germany wants tough fiscal controls for every eurozone country to come out of this. And, as one official said to me, at times like this, what Germany wants, Germany tends to get.
But outside Germany, the worry is that the big losers in all this won't be speculators - but ordinary citizens in countries like Spain and Portugal who find they cannot combine massive budget cuts with decent economic growth.
Make no mistake, the UK and the rest of the world will suffer as well, if the conclusion of this crisis is a eurozone based on the same export-led growth model as Germany.
The rest of the world needs domestic demand in the eurozone to grow, not shrink even further, in the next few years. But right now it is very difficult to see how that will happen.
Indeed, if Germany has its way, the eurozone is going to make an even smaller contribution to future global growth than we thought.