The payments include the disgorgement of more than $538,000, plus interest, of profits and improper financial benefits, and approximately $559,000 in fines. Citigroup also violated supervisory requirements related to Rule 105; and as part of the sanction, the firm was ordered to update its written supervisory procedures for Rule 105 compliance.

Rule 105 of Regulation M under the Securities Exchange Act of 1934 generally prohibits buying securities in secondary offerings when the purchaser sold short the security that is the subject of the offering during a specific restricted period - typically five business days - before the secondary offering is priced.

From May 26, 2009, to September 21, 2010, Citigroup sold securities short within the five business days leading up to the pricing of five public offerings in those securities, and then purchased securities in those offerings. Citigroup purchased a total of more than 1.5 million shares after having sold short 313,890 shares of the securities within the five business days leading up to the offerings.

Thomas Gira, FINRA Executive Vice President, Market Regulation, said, "Rule 105 of Regulation M remains vital to protecting the integrity of the offering process by prohibiting firms from engaging in certain prohibited activities before the pricing of secondary offerings. FINRA will continue to aggressively monitor firms for adherence to Rule 105's requirements and adequate supervisory systems to ensure such compliance."

In concluding this settlement, Citigroup neither admitted nor denied the charges, but consented to the entry of FINRA and BATS' findings.

[1] The settlement with BATS will become final and conclusive on April 9, 2014, unless called for review pursuant to BATS Rule 8.10(c).