Found 2 exchanges where IoTeX is traded for BTC. According to the data on 6 September the most optimal price to exchange IOTX for BTC is ₿0.00000004 for 1 IoTeX. This rate is fixed at Upbit at the maximum trading volume of the pair IOTX/BTC - 0.2 BTC.
The maximum daily trading volume is observed in the IOTX/USDT trading pair at BitDelta and reaches ₿ 120.98 (0.424% of the exchange's total trading volumes) at the price ₿ 0.000000039 per 1 IOTX.
The minimum price to buy IOTX for BTC is 0.00000003 - on the exchange Upbit Indonesia.
The maximum price to buy IOTX/BTC is 0.00000004 - on the exchange Upbit.
Warning: some IOTX markets show an abnormally wide spread — those quotes may be unreliable (thin liquidity or off-market trades). Cross-check the volume against several venues.