On the 19th floor of a tower block in Canary Wharf, the real world seems a very long way away. A rather excitable man is shouting something in French, while another is chewing gum and yelling in a language I take to be English, only it might as well be Ancient Greek for all that I can understand. “Forty-nine bid three-year threes,” he bellows, twice. “Got it, guys?” His colleagues on the dealing floor of BGC Partners did, presumably, get it: but any stranger passing by might wonder whether he had strayed into some secret society where they speak a coded language understood only by a chosen few.

“Four-and-a-half bid ten!” “64 64-and-a-half outright ten years!” As the pace quickens and the brokers shout louder and louder, I have a nagging suspicion that I should probably care a great deal about what these men are on about. If only any of it made sense.

Brokers arrived expecting to be immersed in a market bloodbath as the fallout from Monday’s failure of American politicians to agree a bailout plan was digested. But, and the outsider may demur, this was apparently a sedate day. David Buik, a partner with BGC, said: “Everyone came in today thinking it was going to be rock’n’roll territory but it was actually quiet.” A broker added: “It’s cold and wet. Just like the market.”

But here, high above the streets, millions of pounds are changing hands every second. On the foreign exchange options desk, deals are often for hundreds of millions of dollars.

The same thing is happening in dealing rooms across the rest of Canary Wharf and the City, and by the time this lot pack up at the end of the day, another group of shouty young men will take over in New York, succeeded in turn by their equivalents in the Far East, before Asia finally hands back over to London again in the morning.

Why? And what does it mean for the rest of us?

BGC Partners is an international money broker. Its clients are the big banks, the tools of their trade are whizzy financial products such as futures and interest-rate swaps. By making judgments about what the pound is going to do against the dollar, say, or how various different interest rates will behave, the banks can make money that they could not make otherwise. “They enhance the value of the banks’ balance sheets,” Mr Buik said. “They are very liquid and easy to get rid of.”

Take the other day, for instance, when the news of the nationalisation of Bradford & Bingley emerged. “Dollar-sterling was about $1.83,” Mr Buik said. “People thought that it showed a huge sign of weakness for sterling, because of the underlying concern that perhaps the UK banking system might have the same problems as the US. Banks used brokers to sell sterling and buy dollars at $1.83, then reversed the trade to buy back sterling at $1.80.”

Sterling did indeed end up at $1.80 a few minutes later, and someone made a lot of money that day.

It is lunchtime, and after a quiet morning the pace is picking up again. New York is about to open and President Bush is making his statement before the markets begin. Some of the brokers are standing at their desk, waving their phones about and shouting at colleagues: that’s what they do when it gets exciting. A skinny dealer dressed all in black is swearing down the phone in Italian.

Mr Buik is convinced that Congress will be able to thrash out a deal because he cannot envisage a world without it. Wall Street may be unpopular with US politicians but to him the banks are a financial fact of life, and one that should be faced up to.

“If anybody does not believe that banking is the artery to the infrastructure and fabric of life, then they are living on the planet Zog. If you cannot borrow money at a decent rate, if you cannot get a mortgage, if industry and commerce is incapable of raising debt, then unemployment goes through the roof, retail collapses and you have anarchy.”

At the end of the day, the brokers pack up, take the lift down and go home. For a few hours, they are out there with the rest of us in the real world, the world of jobs and mortgages and pay packets. But they will be back on the 19th floor in the morning.

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