This paper investigates how the aggregate mining power of blockchain affects the market quality of cryptocurrency trading platforms. Using historical intraday data of three cryptocurrencies traded on three platforms from January to June 2021, we observe that a decrease in the blockchain’s aggregate mining power results in wider price discrepancies across platforms and reduced liquidity. We also analyze abnormal hashrate and find consistent results that support our previous findings. The contribution of this study lies in empirically exploring the connection between blockchain mining and the trading environment of the crypto market, highlighting the importance of considering the impact of blockchain validation process when designing fair and efficient markets for crypto assets.