Our analysis revealed a significant decline in the quality of information shared on Twitter/X following the platform’s ownership transition. Before the acquisition, both the Twitter panel and Decahose datasets exhibited slight improvements in information quality before the acquisition on October 27, 2022, but after the transition, this trend reversed, leading to a measurable decline in the credibility of shared sources. This pattern is evident across different measures of credibility and was confirmed by an interrupted time series (ITS) analysis, which detects a sharp decline immediately after the acquisition, followed by a sustained downward trend. These findings suggest that changes in platform governance and user behavior correspond with a deterioration in the quality of shared content.