Pigeon/banker joke of the day

It's very rare you can find a joke involving both pigeons and bankers. So it's with great pleasure that I present this credit crunch gem:

What’s the difference between a stockbroker and a pigeon? A pigeon can still leave a deposit on a Porsche.

Thanks to the FT and LibertyCat who tells me that, to make the joke perfect, it just needs to incorporate a ferret's mother-in-law.