Federal prosecutors and regulators are investigating whether "market manipulation or other types of misconduct" led to a meteoric rise in shares of companies such as GameStop and AMC, the Wall Street Journal reported on Thursday.
The Justice Department's fraud section and the San Francisco U.S. attorney's office have sought information about the trading from brokers and social-media companies that were hubs for the trading, the WSJ reported, citing people familiar with the matter.
Prosecutors have subpoenaed information from brokers such as Robinhood, according to the report.
Additionally, the Commodity Futures Trading Commission has opened a preliminary investigation into whether misconduct occurred as some Reddit traders targeted silver futures, the WSJ report.
A Justice Department spokesperson did not immediately respond to a Reuters request for comment.