Found 10 exchanges where Monero is traded for BTC. According to the data on 17 July the most optimal price to exchange XMR for BTC is ₿0.0053 for 1 Monero. This rate is fixed at KuCoin at the maximum trading volume of the pair XMR/BTC - 62 BTC.
The maximum daily trading volume is observed in the XMR/USDT trading pair at KuCoin and reaches ₿ 759.52 (5.49% of the exchange's total trading volumes) at the price ₿ 0.0053 per 1 XMR.
The minimum price to buy XMR for BTC is 0.0052 - on the exchange Poloniex.
The maximum price to buy XMR/BTC is 0.0053 - on the exchange SafeTrade.