The issue becomes just the latest in a long list of issues the SEC is examining regarding the current U.S. market structure, right up there with high frequency trading, dark pools, flash trading, market access, and trade tracking and reporting.

FORBES: SEC Takes Aim at Wild Market Swings

In reality, the markets (in part driven by privately held firms like Getco) have been evolving to a structure that caters to electronic trading, high frequency or otherwise.

FORBES: Out With the Old, In With the New