Can't speak about London, but 5/100th of a per cent strikes me as a *lot*. There are people who arbitrage stocks vs. futures for that kind of money (5 basis points), so this kind of proposal would indeed drive business away from the NYSE, towards the electronics exchanges.

You misread the proposal. It's not 5/100 of a percent (.05%)-- which might be seen as significant, but 5/100 of a cent, a penny, per share. So on a share of $20, that would add up to .0025%, an order of magnitude less.

Actually, Andrew is right -- the language in the article is somewhat confusing, but the average rate works out to 5 basis points, i.e. 5 one hundredths of a percent of the value of the trade.

That's between 10 and 15 percent of average transaction costs at present, enoguht to bring them back up to where they were in 1998 or so.

Trading on ECNs is much thinner, so the difference in transaction costs is generally going to be a lot more than 5 basis points. Of course (as I told the News) some trades would move, but the question is, how many? Given the existing cost advatage of the NYSE for the vast majority of trades, I think the answer is, Not many.