Through various means, Ristow misrepresented himself in accumulating shares of 23 mutual banks-including City Savings Financial Corp. in Michigan City, the SEC said. He amassed the shares hoping to make money as the banks converted to stock ownership and launched initial public offerings.
Ristow forfeited $2.85 million of illegally gained profits in connection to his guilty plea in New Jersey. Additional criminal penalties might be forthcoming.
The SEC said the fraud took place between 1994 and 2007.
Ristow's attorney, James Hanlon, said in a statement that Ristow cooperated with the government and accepts responsibility for his actions.
"Mark Ristow is an honorable man who made some bad decisions in his investment activities," the statement said. "These decisions were out of character and Mr. Ristow profoundly regrets having made them."
Ristow, who received an MBA from Harvard University in 1971, is a former real estate entrepreneur, the SEC said.