PANews reported on June 5 that according to Reuters, Massachusetts securities regulators are investigating GameStop (GME.N) trading activities and the trading activities of well-known investor Keith Gill (known as "Roaring Kitty"). A spokesman for Bill Galvin, head of the state's top securities regulator, confirmed that Gill's activities were being investigated but declined to comment further.

Earlier, Gill posted on Reddit that he had bet $116 million on GameStop, causing GameStop's stock price to surge on Monday. The stock price subsequently fell by about 5%. The post also suggested that Gill may have made tens of millions of dollars in paper profits on GameStop options. Reuters was unable to independently verify the authenticity of the post and the position, and was unable to immediately contact Gill for comment.

Regulatory investigations do not usually indicate violations and do not lead to enforcement actions. Galvin investigated Gill's 2021 activities, but closed the case after reaching a settlement with Gill's former employer MassMutual for improper supervision. Screenshots of GameStop transactions on Reddit sparked a "network stock" craze, but the U.S. Securities and Exchange Commission (SEC) found that the market system was operating well after an investigation and found no evidence that short sellers were driving the craze.