My uninformed opinion is they are coordinating because this is a global problem, and the more institutions involved will bring greater confidence to the markets.
I agree that this is a global problem — we’ve been seeing signs of that since August quite well.
What I’m not sure of is whether this increases or decreases confidence. Because this unprecedented effort without any background information is doing just the opposite for me - it leaves me asking more questions that they aren’t about to answer.
Every announcement by the Fed this morning on this deal makes it look more and more like they know there’s some huge, “can’t fail” bank that’s teetering on the edge, they all know it has ramifications for both the EU and the US (otherwise it would have been impossible to get both the ECB and BOE on board with the Fed on this deal), but they’re going to be real cute and not say who/what it is.
At times like this, I come back to one truth about the markets: they hate uncertainty.