Ex-congressman, banker and F.B.I. trainee are charged with insider trading.

A former Indiana congressman, an F.B.I. trainee, a Wall Street banker and several others made for an unlikely grouping when the federal authorities on Monday announced the filing of criminal and civil insider trading charges against nine people in a set of unrelated cases.

The series of cases, brought by the U.S. attorney in Manhattan and the Securities and Exchange Commission, indicate that a decade after the federal authorities mounted a crackdown on insider trading in the hedge fund industry, trading on confidential information about impending corporate deals remains enticing to some. In all, the authorities said the schemes netted more than $7 million in illegal trading profits.

“As today’s actions show, we stand ready to leverage all of our expertise and tools to root out misconduct and to hold bad actors accountable no matter the industry or profession,” said Gurbir S. Grewal, the S.E.C.’s director of enforcement.

In filing criminal and civil securities fraud charges against Stephen Buyer, a former Indiana congressman, the authorities said Mr. Buyer misused confidential information about a telecom merger he had obtained while working as a corporate consultant.

Mr. Buyer, a Republican who left Congress in 2011, traded on one tip that he received in 2018 during a golf outing with an executive from T-Mobile, which was one of his clients, according to the charging documents. The executive had mentioned the company was soon to announce a deal to merge with Sprint and in advance of the deal, the authorities said, Mr. Buyer and two other people acquired shares of Sprint and made a profit of more than $107,000.

On a tip involving another telecom deal in 2019, Mr. Buyer made more than $227,000 in profits, the authorities said, by trading on information he had received from one of his clients about a deal to buy another company.

Andrew Goldstein, a lawyer for Mr. Buyer, said his client was innocent and “his stock trades were lawful.”

The authorities also filed charges against Brijesh Goel, an investment banker, who traded on confidential information he received in 2017 while working at his firm. Mr. Goel, according to the authorities, made illegal trades with a friend ahead of corporate acquisition announcements that generated profits of more than $275,000.

Federal prosecutors in Manhattan and the S.E.C. did not identify the investment bank where Mr. Goel worked. But a LinkedIn profile for Mr. Goel said he worked for Goldman Sachs from 2013 to June 2021. Mr. Goel currently works for Apollo Global Management, the private equity firm. An Apollo spokesman said that “upon learning of the allegations for the first time this morning,” Mr. Goel was placed on “indefinite leave.” A Goldman spokeswoman did not respond to a request for comment.

A lawyer for Mr. Goel was not immediately available for comment.

The authorities also charged Seth Markin, a former F.B.I. trainee, with making $82,000 in illegal trading profits by misappropriating confidential information about a pending deal involving the drug company Merck. Federal prosecutors and regulators said Mr. Markin traded on information he got after secretly reviewing a confidential deal binder belonging to his then girlfriend.

Mr. Markin, according to the charging documents, shared the tip with a friend who also traded on the information.

A lawyer for Mr. Markin was not immediately available for comment.

Damian Williams, the U.S. attorney for the Southern District of New York, said, “The message of today’s arrests is simple: My Office remains as committed as ever to rooting out insider trading in all forms.”