volatility of carbon emissions, it is not surprising that crude oil and coal have recently become a very important research topic … causality and volatility spillovers in spot and futures prices of carbon emissions, crude oil, and coal. A likelihood ratio test … is developed to test the multivariate conditional volatility Diagonal BEKK model, which has valid regularity conditions …

We analyze (frequency) connectedness and portfolio hedging among U.S. energy commodities from 1997 to 2023. We show … that the total connectedness increased over time, likely due to the increasing financialization of energy commodities. It … diversify an energy portfolio during distress periods, adding natural gas seems to bring non-marginal diversification benefits. …