I understood barely half of the words in the title. I must be getting old.
What continues to astound and fascinate me is how after all this time we still have so many different crypto currencies. Also, how so many of them manage to retain value after massive violations of trust and failures.
- Transaction fees when you transfer funds in or out of your wallet. (or they buy and sell at different prices which amounts to the same thing in the end)
- Float on deposited funds
- A few make money on other transactions or on mining.
The different currencies operate differently so the ways to make money as an exchange vary, but transaction fees are usually the big way.