The Business On... Bob Greifeld, Chief executive, Nasdaq OMX

So the marathon man is back

Now, that would be running before you can walk. But a number of City gossips are tipping Bob Greifeld, the marathon-running chief executive of America's Nasdaq stock exchange, as the man behind the "approach" that the pan-European share trading firm Chi-X has had from a third party.

Erm, didn't he have a company like that?

It's true that his Nasdaq OMX in April abandoned an 18-month attempt to break into pan-European share trading by announcing the closure of "Nasdaq OMX Europe". But Chi-X has something that Nasdaq OMX Europe never managed: liquidity. In other words, a lot of people use it, which happens to be crucial if you are running an exchange. And if you can't do something yourself, best to buy someone who can.

That would mean a head-to-head with the Stock Exchange

Oh yes. The London Stock Exchange has a very similar operation to Chi-X known as "Turquoise". Basically, what these operations do is allow institutions to trade big blocks of shares without other traders picking up on what's going on and moving the price against them.

Didn't Greifeld once try to takeover the LSE?

He did. Twice. And was less than happy when he got turned down. If Nasdaq got hold of Chi-X it would certainly be an issue for the LSE and its French chief executive, Xavier Rolet, although, to be fair, there is also rumoured to be interest from others, such as Deutsche Börse.

Why'd he lose?

It didn't help that he spent rather a lot of time conducting the hostile takeover battle for the LSE in New York. Or that the LSE's then boss, Clara Furse, didn't want to speak to him. But Mr Greifeld, who at the age of nine walked the streets of the Big Apple delivering newspapers while his father delivered letters, is nothing if not persistent. He has been at Nasdaq since 2003 and has lost none of his ambition.

Sounds like fun times in exchange land

Yes. On the face of it, it all appears rather arcane. But buying Chi-X would give Mr Greifeld a chance to show LSE investors what they were missed when they turned him down.