This paper investigates the causal relationship between Distributed Ledger Technology (DLT) settlement latency and market quality in the cryptocurrency domain. Utilizing the cryptocurrency market as a unique laboratory, we identify blockchain mining power as an instrumental variable for DLT settlement latency. Our analysis reveals that DLT settlement latency significantly lowers liquidity and increases transaction costs. In addition, through the Huang and Stoll (1997) spread decomposition, we document that DLT settlement latency reduces the adverse selection costs and increases the inventory management costs faced by liquidity suppliers. Moreover, these effects are more pronounced in smaller trading venues and for the native cryptocurrency of the settlement blockchain. More broadly, this paper contributes novel evidence on the importance of settlement, and highlights the balance between decentralized, near-instantaneous settlement cycles offered by DLT and the potential adverse impacts on market quality.