Poloniex an exchange owned by Circle, a company who also launched the stable coin USDC, is a popular crypto-to-crypto exchange.
Poloniex doesn’t operate in every state, but in the states it does operate in it is a valid choice for crypto-to-crypto trading.
They stand out in that they have a reputable parent company, are a long standing exchange, and are closely related with the popular US regulated stable coin USDC.
They also began standing out from the pack in Nov 2018 when they announced pre-trading on the Bitcoin Cash fork Bitcoin SV.
Traders in New York, Washington State, and a few others will have to look elsewhere, but generally speaking Poloniex is a solid choice for a crypto-to-crypto exchange that pairs well with Coinbase (where you can convert dollars to USDC).
"Poloniex" contains information about the following Cryptocurrencies: