Detecting and Quantifying Wash Trading on Decentralized Cryptocurrency Exchanges Friedhelm Victor Andrea Marie Weintraud Technische Universität Berlin Technische Universität Berlin Berlin, Germany Berlin, Germany
[email protected] [email protected] ABSTRACT the umbrella term Decentralized Finance (DeFi) are establishing Cryptoassets such as cryptocurrencies and tokens are increasingly themselves as a key use case for distributed ledger technologies traded on decentralized exchanges. The advantage for users is that (DLTs) in general. The aim is to design financial products, that are the funds are not in custody of a centralized external entity. How- partly based on services from the traditional financial world yet ever, these exchanges are prone to manipulative behavior. In this completely new in other areas. The appeal lies in offering these paper, we illustrate how wash trading activity can be identified financial products in a decentralized way, excluding middlemen as on two of the first popular limit order book-based decentralized far as possible. exchanges on the Ethereum blockchain, IDEX and EtherDelta. We While the field now encompasses a multitude of services suchas identify a lower bound of accounts and trading structures that meet lending protocols, derivatives and insurances, so-called decentral- the legal definitions of wash trading, discovering that they arere- ized exchanges (DEX) were among the early drivers of the ecosys- sponsible for a wash trading volume in equivalent of 159 million tem. They allow for the exchange of virtual assets without having to U.S. Dollars. While self-trades and two-account structures are pre- rely on externally-controlled services such as centralized exchanges, dominant, complex forms also occur.