This is a story from August 2023, and was covered in many outlets (I quote here NYT for reference only)

Federal regulators continued their crackdown against employees of Wall Street firms using private messaging apps to communicate, with 11 brokerage firms and investment advisers agreeing Tuesday to pay $549 million in fines.

Wells Fargo, BNP Paribas, Société Générale and Bank of Montreal were hit with the biggest penalties by the Securities and Exchange Commission and the Commodity Futures Trading Commission. Together, the brokerage and investment advisory arms of those four financial institutions accounted for nearly 90 percent of the fines, according to statements released by the regulators.

Original NYT

Archived version