Citigroup analyst Kevin Chang emailed unpublished research about Hon Hai Precision Industry Co., a major supplier of Apple Inc. iPhones, to Steven A. Cohen's hedge fund SAC Capital Advisors, T. Rowe Price, Citadel and GLG Partners, according to William Galvin, Massachusetts' Secretary of the Commonwealth.

Chang's research included lower order forecasts for Apple's iPhones in the first quarter of 2013, which would have had a detrimental effect on Apple, the regulator said.

SAC, hedge fund Citadel and mutual fund firm T. Rowe Price all sold Apple stock after receiving the information from Chang, a complaint filed by Galvin's office alleges.

At $30 million, the Massachusetts fine is both one of the biggest state securities regulators have ever collected and 15 times the $2 million they fined Citi for improperly disclosing research on Facebook's initial public offering only a year ago.

Galvin said the fine is so high because the case came less than one year after the Facebook case and illustrates that aspects of Citi's supervisory culture failed.

"The Citi analyst should not have been that accessible to the clients, he should have been better protected by the compliance team," Galvin added.

Galvin's office had filed civil charges against Citi for "failing to supervise", and the $30 million fine is the result of a settlement, he said. No criminal charges were filed.

A spokeswoman for Citi said the bank takes "regulatory compliance requirements very seriously and train(s) all of our employees about these obligations." She declined to give further details about the case.

Chang, who worked for Citi in Taiwan, was terminated last month, the complaint said.

The Massachusetts settlement also offers new details about how SAC employees worked at a time the $14 billion hedge fund has come under increased scrutiny about its trading practices. The U.S. government filed criminal insider trading charges against SAC in July. The hedge fund said it has done nothing wrong and pleaded not guilty to the charges.

Galvin said he would be happy to cooperate with federal or other state authorities probing SAC.

"The emails between Kevin Chang and the hedge funds reveal this cozy culture which illustrates again that there are two types of customers; big ones and retail customers who often dont' receive this information," Galvin said in a telephone interview.

The complaint cites an email from an unidentified SAC employee who asked a contact at Citi "can u send me everything u have on the entire iphone 4/4s/5 supply chain?.

Citi employees responded immediately by asking their colleagues "can you please send directly to (employee for SAC Capital) ... He needs it asap - works directly for (SAC Capital).'

Chang was also contacted directly by a SAC employee. "Hey Kevin, Are you picking up any order cuts to iPhone?" the email said.

Kevin Chang sent his unpublished research which included the Hon Hai numbers and unpublished research for Apple iPhone order forecasts to the SAC employee on December 13, 2012. Chang's research was published on December 14.

A SAC spokesman said he has no comment on the matter.

Chang also received emails from Citi colleagues saying that other big clients, including Citadel, wanted his views on Apple. A Citadel employee emailed Chang on December 13 saying "Can we do a quick call tonight?"

In the securities industry, Galvin, who has been in the job for 18 years, has a reputation as an aggressive regulator happy to take on Wall Street banks in order to protect small, private investors. In 2011, Goldman Sachs agreed to pay a $10 million fine and stop giving clients trading ideas developed at internal gatherings known as "trading huddles."