Data from an anonymous researcher hildobby shows that in 2022, brushing/cleaning transactions will account for more than half (58%) of the total NFT transaction volume on the Ethereum chain, totaling more than $30 billion.
The strategy peaked in January, accounting for more than 80% of total NFT trading volume that month. The researchers used four filters to weed out unusual trading behavior that most likely pointed to wash trading. First, they filter out obvious NFT transactions between the same wallet address.
Second, they study the back-and-forth transactions of the same NFT between two different wallet addresses, which is one of the most common virtual transaction strategies. Third, if a wallet address purchases the same NFT three or more times, it is marked as a brush transaction.
Finally, if the wallets of the buyer and seller in an NFT transaction are initially funded by the same wallet, then it is clear that there is a connection between them and thus be flagged as a spam transaction. Hildobby attributes the increase in brush trading activity to increased competition among NFT markets for market share in trading volume.