Crypto Trading: USD as a Base Currency

I have accounts in Bittrex but I think it's difficult to calculate real return due to the price volatility of BTC itself. I tried bitstamp as well but it has very limited currency pairs so it's worthless

It seems their is a gap currently with none of exchanges offering USD as the base against a basket of Cypto currencies and alt coins. If you know about such platform, please post in the comments, will really appreciate your feedback.

Coin Marketplace

STEEM 0.17
TRX 0.16
JST 0.029
BTC 75924.44
ETH 2901.21
USDT 1.00
SBD 2.67