Wash trading is illegal in many regulated markets, including traditional stock exchanges and cryptocurrency exchanges, as it creates a false impression of liquidity and market activity. It can be used to manipulate the price of an asset, making it appear more popular or volatile than it actually is. This deception can mislead traders and investors, causing them to make decisions based on artificially inflated market conditions. Wash trading can also be used to generate tax advantages by creating the appearance of a legitimate trade.