The securities regulatory authority in Massachusetts, USA, has launched an investigation into the trading activity of GameStop, a popular video game retailer. The authority has confirmed that they are scrutinizing the actions of Keith Gill, a prominent investor known as 'Roaring Kitty', who has been linked to a significant surge in GameStop's US stock.

On June 3, GameStop's US stock had skyrocketed by 110% in pre-market trading, sparking widespread interest and speculation. A post on Reddit had claimed that Keith Gill had built a position worth $181 million in GameStop, further fueling the speculation. The investigation is ongoing, and further details are yet to be released.

The Massachusetts securities regulatory authority is tasked with ensuring that the securities market is fair and transparent. The investigation into GameStop's trading activity is a significant development, as it highlights the authority's commitment to protecting investors and maintaining market integrity.

The investigation is likely to focus on Keith Gill's trading activities, including his purchases and sales of GameStop stock. The authority may also be examining the role of other investors and market participants in the surge in GameStop's stock price.

In conclusion, the investigation into GameStop's trading activity is a significant development in the world of finance. The Massachusetts securities regulatory authority is taking a proactive approach to ensuring that the securities market is fair and transparent, and the investigation into Keith Gill's actions is a testament to the authority's commitment to protecting investors and maintaining market integrity.