Curbs on high speed trading in US markets appear inevitable as policymakers pore over the sequence of events that led to the dizzying plunge in the Dow Jones Industrial Average last week.
The SEC in conjunction with US exchange has already agreed to the uniform introduction of circuit breakers - master switches that are designed to trip during volatile trading.
However, the probe into the crash has so far failed to identify a single event which could be the sole cause, leading the SEC's Mary Schapiro to speculate in testimony to Washington lawmakers that the disruption may have been the result of "a confluence of events which, taken together, exacerbated what already had been a down day and led to an extraordinarily steep price drop and recovery".
Speaking at the same hearing, CFTC commissioner Bart Chilton drew attention to the role played by technology in transforming trading practices in the modern era.
"The new and innovative trading practices that are currently in use (and being developed) have simply moved beyond regulators' ability to keep up with in a timely fashion," he said. "Regulators need to do more to ensure that fintech works for us or it will, as we have seen, work against us."
Pointing to the sheer size and speed of the trading that moved the markets last week, Chilton said there could be no doubt that the collapse and ultimate rebound was affected in some way by technology.
"Without fully understanding all of the ramifications of this technology however, we will continue to witness market aberrations," he noted. "Perhaps there should be certain limits or parameters on fintech trading? Perhaps the size of trades should be regulated, or the time period in which they could occur should be limited or more closely monitored? These questions and many others need examination in detail, and urgently, by regulators, exchanges and policymakers."
The point was picked up in testimony given by Nyse Euronext COO Larry Leibowitz.
"The trading events of May 6 are indicative of broader changes to markets and trading practices for which recent advances in technology have been a catalyst," he said. "The...market drop certainly should inform the SEC's current examination of the changes in the markets, and in particular how certain advances in technology may have fostered trading practices that negatively impact the entire market."