This study aims to examine how firms use operational announcements to signal supply chain resilience during large-scale disruptions. Focusing on periods of heightened uncertainty, it investigates whether disclosure frequency and tone shape investor reactions differently across industries with varying supply chain exposure. The purpose is to clarify when transparency stabilizes external expectations and when communication loses effectiveness under systemic disruption.
Using a short-window event study, the analysis evaluates abnormal stock returns surrounding firm-level operational announcements issued during a major disruption period. Announcements are manually collected from leading US news outlets and classified by sentiment, industry type and technology orientation. Cross-sectional and nonparametric tests are applied to compare market reactions across sectors and announcement characteristics.
The results reveal four consistent patterns. Industries with higher operational exposure issue more frequent and negatively framed disclosures. Investors react more strongly to negative announcements from traditionally stable sectors, indicating expectation violation effects. High-communication sectors exhibit muted market responses consistent with information fatigue. In contrast, traditional industries generate stronger abnormal returns from positive announcements, reflecting a strategic surprise effect linked to perceived adaptability.
The analysis focuses on short-term market reactions during a single disruption context. Although the empirical setting reflects an extreme global shock, future research could examine whether similar disclosure dynamics emerge under other forms of supply chain disruption, such as geopolitical tensions, trade policy shocks or infrastructure failures.
The findings suggest that public disclosures should be treated as part of supply chain disruption management rather than routine reporting. Transparent communication linked to concrete operational actions can stabilize expectations in high-exposure industries, whereas excessive updates may dilute impact in information-saturated sectors. Managers should align disclosure strategies with industry-specific supply chain vulnerabilities and stakeholder expectations.
This study positions corporate announcements as an operational signaling mechanism within supply chain disruption management. By combining event study evidence with cross-industry analysis, it demonstrates how disclosure strategies interact with supply chain exposure and stakeholder expectations. The research extends supply chain resilience literature by highlighting the external valuation effects of operational transparency under systemic disruptions.
