As part of the research, Bitwise analyzed trading data of some 83 exchanges. Researchers said they looked at the trade size histograms, volume spike alignment and spread patterns of these exchanges. They concluded that there are only 10 exchanges with 100% real trading volumes, and these 10 exchanges collectively account for 5% of the reported trading volume.
Bitwise classifies the 10 exchanges as real volume exchanges or reference exchanges. The 10 exchanges include Binance, Bitfinex, bitFlyer, Bitstamp, Bittrex, Coinbase Pro, Gemini, itBit, Kraken and Poloniex. Among the 73 exchanges that Bitwise condemned as displaying fake volumes are OKEx, HitBTC and Huobi.
As expected, there were questions raised about the reliability of the Bitwise study considering that these popular exchanges aren't regarded as real volume exchanges. Bitwise pointed out that the trading data of the three exchanges doesn't follow that of Bitwise's real volume exchanges. It also referenced existing research that found similar patterns with the three exchanges to support its findings.