List of Cryptocurrency Marketplaces Operating in the USA

As of my last knowledge update in September 2021, here are some popular cryptocurrency exchanges that were operating in the USA:

1. Coinbase: Coinbase is one of the largest and most well-known cryptocurrency exchanges in the world. It is based in San Francisco, California, and is one of the most popular choices for buying and selling a variety of cryptocurrencies.

2. Kraken: Kraken is another popular cryptocurrency exchange that offers a wide range of cryptocurrencies for trading. It is based in San Francisco and is known for its security features and extensive list of trading pairs.

3. Binance.US: Binance.US is the US-based arm of the global cryptocurrency exchange Binance. It offers a selection of cryptocurrencies for trading and is popular among traders for its low fees.

4. Gemini: Gemini is a cryptocurrency exchange founded by the Winklevoss twins. It is known for its focus on security and regulatory compliance and is a popular choice for both retail and institutional investors.

5. Bittrex: Bittrex is a US-based cryptocurrency exchange that offers a large number of trading pairs and has a reputation for its security measures.

Please note that the cryptocurrency exchange landscape is constantly evolving, so there may be new exchanges that have emerged since my last update. Additionally, regulations and availability of certain exchanges may have changed since then. I recommend checking for the latest information on cryptocurrency exchanges operating in the USA.