Skip to content

Citadel Securities Loses Flash-Boys Legal Fight Over IEX Product

  • Appeals court upholds SEC approval of exchange’s D-Limit order
  • Citadel sued SEC, alleging regulator botched approval process
Ken Griffin

Ken Griffin

Photographer: Patrick T. Fallon/AFP/Getty Images

Updated on

Citadel Securities LLC lost its case against the SEC over a market order type from the IEX exchange of “Flash Boys” fame that features a 350-microsecond delay, after arguing the regulator botched its approval. 

A trio of federal judges in Washington on Friday upheld the US Securities and Exchange Commission’s decision on the order type, the exchange operator’s D-Limit, whose delay is meant to reduce the advantage of high-frequency traders. The electronic trading firm founded by billionaire Ken Griffin argued that D-Limit hurts investors by delaying their orders and that the SEC approval process broke the laws and rules that govern it.