Working with colossal trade sizes, you can almost eliminate fees.
Poliniex is one of the most famous crypto world exchanges
Poloniex have advance trading tools like dozens of technical indicators. They have robust API for that.They have a clod storage for your money what ever you have for better saftey. They check activity regularly to avoid spam.
Poloniex provides some of the lowest fees around, with the highest taker fee set at 0.25% when trading under 600 BTC.
Poloniex have Margin Trading and Lending