At Advanced Trading's Peer-to-Peer Multiasset Class Trading Executive Roundtable yesterday, a couple of roundtable delegates wondered where all of the order flow and liquidity has gone and pondered whether the markets will be able to withstand a truly volatile trading day with extremely high trading volumes.While it wasn't a scientific poll (there were only 14 executives in the room), the general consensus is that liquidity is harder to find and is more fragmented. A couple of executives wondered if Reg NMS, the regulation that was supposed to make markets more transparent, have in fact made them harder to navigate. One trader quipped that the traders on his firm's floor joke that Goldman Sachs must have all of the order flow, indicating some good natured (or not) Goldman-envy.

In any event, it is interesting. Volumes have had their spikes, due to market volatility, but for the most part, volumes have remained relatively stable. One would have thought that post Reg NMS, volumes would increase. But the only thing that is increasing is the number of trade messages. One attendee commented his firm is already seeing a 6x increase in the number of messages it handles daily. He also wondered if the market is really going to be able to handle a truly volatile day when volume is 3 to 5 times normal, noting that the volatile days in August didn't have extremely high volume despite the huge swings in the DJIA.Order flow is dissappearing, according to attendees at a recent Advanced Trading Roundtable.