As of now, there are no specific virtual currency exchanges based in Philadelphia, USA that are considered the largest in terms of trading volume or user base. However, there are several popular virtual currency exchanges that are widely used by residents of Philadelphia and across the United States.

Some of the most popular virtual currency exchanges in Philadelphia include Coinbase, Kraken, Binance, and Gemini. These exchanges offer a wide range of cryptocurrencies for trading, as well as various features and services for users to buy, sell, and store their digital assets.

Coinbase is one of the largest and most well-known virtual currency exchanges in the United States, offering a user-friendly platform for buying and selling a variety of cryptocurrencies. Kraken is another popular exchange that offers advanced trading features and a wide range of cryptocurrency pairs for trading.

Binance is a global virtual currency exchange that is widely used by traders around the world, offering a wide range of cryptocurrencies for trading and competitive trading fees. Gemini is a New York-based virtual currency exchange that is known for its strong security measures and regulatory compliance.

While there may not be a specific virtual currency exchange based in Philadelphia that is considered the largest, residents of the city have access to a wide range of popular exchanges that offer a variety of cryptocurrencies and trading services.