In a must-read essay, Senator Ted Kaufman reveals that - despite all of the talk coming out of Washington - high-frequency trading is set to explode:

We've gone from an era dominated by a duopoly of the New York Stock Exchange and Nasdaq to a highly fragmented market of more than 60 trading centers. Dark pools, which allow confidential trading away from the public eye, have flourished, growing from 1.5 percent to 12 percent of market trades in under five years.

Competition for orders is intense and increasingly problematic. Flash orders, liquidity rebates, direct access granted to hedge funds by the exchanges, dark pools, indications of interest, and payment for order flow are each a consequence of these 60 centers all competing for market share.

Moreover, in just a few short years, high frequency trading - which feeds everywhere on small price differences in the many fragmented trading venues - has skyrocketed from 30 to 70 percent of the daily volume.

Indeed, the chief executive of one of the country's biggest block trading dark pools was quoted two weeks ago a