1. Safety is an eternal theme in the maritime world. Along with the sustainable development of the international shipping industry and the rising ocean economy, people are increasingly concerned ab...

We examine the impact of upper (lower) market volatility and skewness risks on stock returns. Our results show that market volatility and skewness risks have no significant effect on future stock returns. However, when separately considering call and put options, we find a significantly negative relation between innovations in upper market volatility (skewness) extracted from call options and subsequent stock returns. Moreover, the results remain significant after controlling for other known factors included in the factor models or a battery of firm-level characteristics. Our research shows that call and put options contain different information, and are differently priced in the stock market. This study can help explain the inconsistent results of the recent papers on asset pricing about market volatility and skewness.

Against deglobalization and intensifying geopolitical conflicts, maritime bulk commodity supply chain vulnerability and resilience governance are strategic priorities for 75% of countries. To tackle rising global uncertainty, this study proposes the country-level risk identification, monitoring, and extrapolation (RIME) framework for such supply chains, which aligns with the theoretical demand for macro, end-to-end risk integration beyond the traditional firm-level focus. Based on the “supplier country–shipping route–importing country” spatiotemporal linkage, we construct the first standardized country-level vulnerability index. It overcomes the limitations of existing static and localized assessments by integrating spatiotemporal, multi-source risks across the full physical chain, thereby enabling dynamic, macro-level monitoring and supporting systematic diagnostics and trend tracking of national supply chain security. We also develop an emergent risk simulation technique to quantify the direction and intensity of compound disturbances as well as the system’s dynamic responses. Empirical validation with China’s iron ore imports shows that the index effectively captures risk evolution, while the simulations confirm that sudden disruptions amplify systemic risk. This framework fills national strategic security theoretical gaps and provides governments with dynamic monitoring, quantitative assessment, and policy forecasting tools.