Exchanges are literally printing money. I think nearly a million Ether a day was traded on Gdax at the top. At $1,400 you're talking $1.4bn a day in trading vo

Exchanges are literally printing money. I think nearly a million Ether a day was traded on Gdax at the top. At $1,400 you're talking $1.4bn a day in trading volume, on (at least) half of which they take a 0.3% fee. That's $2.1m a day, just from ETH. Then there's Bitcoin and Litecoin. Bitcoin probably makes a similar amount. And their "simplified" website on which they charge higher fees.