Found 8 exchanges where Zcash is traded for BTC. According to the data on 4 August the most optimal price to exchange ZEC for BTC is ₿0.0076 for 1 Zcash. This rate is fixed at HitBTC at the maximum trading volume of the pair ZEC/BTC - 2.6 BTC.
The maximum daily trading volume is observed in the ZEC/USDT trading pair at Poloniex and reaches ₿ 698.5 (7.33% of the exchange's total trading volumes) at the price ₿ 0.0075 per 1 ZEC.
The minimum price to buy ZEC for BTC is 0.0075 - on the exchange Poloniex.
The maximum price to buy ZEC/BTC is 0.0076 - on the exchange Bitfinex.