Fragmentation of U.S. Equities Market Criticized in SEC Panels

Investors, traders and regulators underappreciate the harm caused by the fragmentation of trading across a dozen public markets with different rules and conventions, said Dave Cummings of Tradebot Systems Inc.

“The market is still very broken and I think the changes we’ve put in place don’t go far enough,” said Cummings, who’s chairman at Tradebot, an automated proprietary trading firm in Kansas City, Missouri. “When you introduce bad data because of ridiculous quotes, that ripples through the whole system and into other markets.” Tradebot accounts for 5 percent to 10 percent of daily equities volume, according to Cummings, who also founded Bats Global Markets, an exchange operator.