Our findings highlight the importance of inventory management. The impact of rebalancing costs due to inventory changes on option spreads far exceeds that of rebalancing costs due to delta changes. Thus, if market makers manage inventories properly and keep their inventories stable, they can substantially reduce rebalancing costs, which in turn lower option spreads and enhance market liquidity. The remainder of the article is organized as follows. Section 2 describes the determinants of option bid–ask spreads and their calculation in this study. In Section 3, we develop our empirical specifications. Section 4 contains the data description and summary statistics. In Section 5,we present and analyze the empirical results. Section 6 provides the results of the robustness tests. Section 7 concludes the paper.