What the SEC Found
According to the SEC's public enforcement release, Citadel Securities claimed it would provide, or try to provide, the best prices for retail orders routed by other broker-dealers. The SEC found that two of Citadel's trading algorithms did not internalize retail orders at the best price observed, nor did they seek to obtain the best price in the marketplace. The SEC concluded this was misleading to the broker-dealers that routed orders to Citadel, as well as to their retail customers.
The Settlement Terms
Citadel Securities agreed to pay $22.6 million to settle the charges. The firm neither admitted nor denied the SEC's findings as part of the settlement — a standard resolution mechanism in SEC enforcement that does not constitute an admission of wrongdoing.
What 'Best Execution' Means
SEC regulations require broker-dealers to seek the best reasonably available price for their clients' orders — a standard known as 'best execution.' Market makers like Citadel Securities receive retail orders from brokers and are expected to provide competitive pricing. The 2017 action indicated that the SEC believed Citadel's execution pricing representations were not accurate.
Ongoing Relevance
The 2017 fine predates ongoing regulatory discussions about payment for order flow and market structure reform. Critics argue that the same structural issues the SEC identified in 2017 — incentives for market makers to retain spread rather than pass it to retail investors — remain present in the current market structure. The SEC has since proposed additional rules to improve order execution quality for retail investors.