There are only 10 exchanges in the "big ones" that have actual volume (Bitmex is ignored they're a derivative exchange, the CME too)
Binance(110M), Bitfinex(38M), Kraken(31M) Bitstamp (31M) Coinbase(27M) bitFlyer(14M) GEMINI(8M) itBit(6M) BITTREX(5M) POLONIEX(1.4M)
The CME does volumes of around 75 million $, so they're quite relevant. If the total is 1.5 billion with Bitmex at 1 bil + the ones listed there + all the small ones, the Chicago Mercantile Exchange does 5% (less since they are closed the weekend).