The regulation of information flow between government officials and firms is crucial in shaping corporate transparency and market dynamics. This paper investigates the impact of the Stop Trading on Congressional Knowledge (STOCK) Act, which creates an exogenous shock by restricting private communication between federal executive branch officials and firms, particularly affecting those with substantial government contracts. Using a difference-in-differences approach, we find that firms with significant government customers reduce the frequency of their management forecasts following the Act's implementation. This reduction is most pronounced in firms where government sales are critical to operations, in those with a strong reliance on political engagement, and in competitive industries. In contrast, non-financial disclosures remain largely unaffected, and the Act's impact on firms tied to Congress members is less significant. Additionally, firms that reduce their disclosures experience a
significant increase in their implied cost of capital. These findings highlight the broader consequences of limiting access to government-sourced information, revealing how regulatory efforts to curb insider trading can unintentionally alter corporate disclosure practices and increase firm financing costs.