SethArb, There is a ring of Electronic Trading screens that encircles the Big S&P pit. These guys are still making money, but the edge has dwindled a bit. In some of the most succesful Electronic contracts, there was an Arb between the Pit and the Electronic market. Their volumes feed off of eachother, but enventually the more efficient platform wins the lion share and the volume. Bunds, Bonds and 10-Year are perfect examples and now the ES is trading more volume from the S&P pit. In any case, the CME wins here, because they get paid for both platforms and volumes are rising . The exchange generates much more revenue from the ES and NQ than is does from the Pits though. Screen Exchange fees are higher that the Pit exchange fees and the volume is much higher on the screens. It is only logical that at some time it will not be cost effective to have both platfroms. I think that it just a matter of time.