what is the Volume and BaseVolume reported from bittrex API?
Volume is the amount traded in that altcoin over the past 24 hours.


In the case of BTC-DGB, this is the amount of DGB that has been traded in 24 hours.


  BaseVolume is the total value traded in the base currency, for example Bitcoin.


Volume increases regardless if it is a buy or sell order.

To find the overall volume you can go to https://coinmarketcap.com.