December 11, 2015
If IEX creating a speed bump puts the HFT-dominated exchange market making system into jeopardy, then the system is too brittle. When compared to exchanges not providing transparency into core order types and operational trade execution -- issues of primary importance -- IEX introducing a speed bump pales in comparison. As Citadel, BATS and NYSE might say, if the market doesn't like the IEX system they have the choice not to use the platform. Let the market decide what's right. As a sidebar, the exchange system that works best is regulated by the CFTC, not the SEC, in my opinion.