Ciamac Moallemi (Columbia) - "Liquidity Provision and Automated Market Making"
Abstract: In recent years, automated market makers (AMMs) and, more specifically, constant function market makers (CFMMs) such as Uniswap, have emerged as the dominant mechanism for trading risky assets on blockchains. On the Ethereum blockchain, for example, such decentralized exchanges are the largest single "application category" implemented through smart contracts, as ranked by resource consumption. Compared to electronic limit order books (LOBs), which are the dominant market structure for traditional, centralized exchange-based electronic markets, CFMMs offer some advantages. First of all, they are efficient computationally. Thus, CFMMs are uniquely suited to the severely computation- and storage-constrained environment of the blockchain. Second, LOBs are not well-suited to a "long-tail" of illiquid assets. This is because they require the participation of active market markers. In contrast, CFMMs mainly rely on passive liquidity providers (LPs). We consider the market microstructure of CFMMs from the economic perspective of the liquidity providers. In a frictionless, continuous-time setting and in the absence of trading fees, we decompose the return of an LP into a instantaneous market risk component and a non-negative, non-decreasing, and predictable component which we call “loss-versus-rebalancing” (LVR, pronounced “lever”). Market risk can be fully hedged, but once eliminated, LVR remains as a running cost that must be offset by trading fee income in order for liqui