تأثیرات پویای اضافی در میان نفت خام، فلزات گرانبها و بازارهای آتی کالاهای کشاورزی

This paper examines spillover effects among six commodity futures markets – gold, silver, West Texas Intermediate crude oil, corn, wheat, and rice – by employing the multivariate DECO-GARCH model and the spillover index. Specifically, we investigate the dynamics of return and volatility spillover indices to reveal the intensity and direction of transmission during the recent global financial and European sovereign debt crises. Our empirical results are as follows. First, we estimate a positive equicorrelation between commodity futures market returns and find that it increased sharply during the crises. This effect can persist during periods of economic and financial turmoil, diminishing the benefits of international portfolio diversification for investors. Second, we identify bidirectional return and volatility spillovers across commodity futures markets, and find more pronounced trends in their levels in the post-crisis period. This indicates the strong impact of spillovers during crisis periods. Third, both gold and silver are information transmitters to other commodity futures markets, while the remaining four commodity futures investigated were receivers of spillovers during recent periods of financial stress. Finally, we analyse the optimal portfolio weights and time-varying hedge ratios between metal and other commodities futures markets. Overall, our findings provide new insights into channels of information transmission, which may improve investment decisions and inform portfolio investors' trading strategies.