The researcher used four filters to weed out odd trading behavior that most likely pointed to wash trading. First, they filtered out obvious trades of NFTs between the same wallet address. Second, they looked at back-and-forth trades of the same NFT between two different wallet addresses – one of the most common wash trading tactics. Third, if a wallet address had purchased the same NFT three or more times, it was flagged as a wash trade because of the unlikeliness of the situation. Finally, if a buyer and seller in an NFT transaction had wallets that were first funded by the same wallet, it was obvious that there was a connection between them and was therefore flagged as a wash trade.