[gumby]

> Is there anything stopping the NYSE, Nasdaq or CME/CBOT from handling trades in another currency?

It would reduce liquidity. Equity prices would fluctuate not only on buy/sell basis but exchange rates. Sure, computers could figure all that out these days but what's the advantage? Overwhelmingly, equity buyers and sellers (not "traders") buy in their local currency because they use the money to live in a local economy.

Companies list in other countries for access to those countries' buyers. What would be the point of Shell listing in Euro on the NYSE? They want to list in dollars. Nobody outside Nigeria lists on its exchange but local companies do because local people understand the companies and everything (both their operations and their stock) is in naira.

So if you want to be an exchange in a different currency, just buy a local exchange. NASDAQ did try to buy the London Stock Exchange, though I think it fell through.