Calling the court’s decision “incorrect” and in “legal error,” SEC Enforcement Division head Robert Khuzami has announced that the agency is appealing a decision by Manhattan federal Judge Jed Rakoff, who last month rejected the SEC’s proposed $285 million settlement with Citigroup Global Markets.

In the largest-ever penalty paid by a Wall Street firm, Goldman Sachs on Thursday agreed to pay $550 million to settle Securities and Exchange Commission charges that it misled investors in a collateralized debt obligation by misstating and omitting key facts. Goldman admitted that it made mistakes and regretted its failure to disclose relevant information. The case was viewed as a bellwether for Robert Khuzami, director of the SEC’s Division of Enforcement, and Chairman Mary Schapiro, who vowed to ramp up agency enforcement.

Saying insider trading has “come back in force,” the associate regional director of the SEC’s New York office said Tuesday that the agency is seeing a “determined business” based on collecting information from corporate insiders.

As the top cop at the Securities and Exchange Commission, Robert Khuzami has spent his first six months as the director of the Division of Enforcement tackling a cleanup of major proportions. He’s undertaken what many call the most sweeping changes of the division in 30 years. Under intense scrutiny from Congress and the SEC’s own inspector general, the agency has come to a watershed moment