A former Wall Street analyst allegedly tipped off a trio of friends to pending corporate transactions, enabling them to repeatedly engage in insider trading.

The U.S. Securities and Exchange Commission (SEC) charged a former analyst for investment firm Blackstone and global investment bank Goldman Sachs, Anthony Viggiano, in connection with an insider tipping and trading scheme.

The SEC alleged that Viggiano had inside information about eight pending deals, and that he tipped off a couple of friends, who traded on the information, and passed along a couple of tips to another college friend.

The regulator’s allegations have not been proven.

Alongside the SEC’s complaint, which seeks civil penalties and disgorgement along with other relief, the U.S. Attorney’s Office for the Southern District of New York brought criminal charges against Viggiano and his two friends.

One of the friends, who was charged with three counts of securities fraud and one count of conspiracy, agreed to plead guilty and is cooperating with U.S. authorities.

Viggiano faces eight securities fraud charges and one charge of conspiracy, and the other friend was charged with three fraud counts and conspiracy. They were both arrested on Thursday. None of the allegations against them have been proven.

The SEC reported that the case originated from its Market Abuse Unit’s Analysis and Detection Center, which uses data analysis tools to detect suspicious trading patterns.

“As alleged in our complaint, Anthony Viggiano violated his employers’ trust by misusing his access to confidential information to repeatedly and unjustly enrich himself and his friends,” said Joseph Sansone, chief of the SEC’s Market Abuse Unit.

“The SEC is focused on detecting misconduct by financial industry professionals, and we will continue to use our resources to bring them to justice and bar them from the securities industry when appropriate,” he said.