GDAX was a cryptocurrency exchange that was later rebranded as Coinbase Pro. GDAX, which stands for Global Digital Asset Exchange, was originally launched by Coinbase in 2015 to provide a more advanced trading platform for cryptocurrency enthusiasts and professional traders.

Here are some key points about GDAX (now Coinbase Pro):

1. **Operational Change:** In June 2018, GDAX underwent a rebranding and became known as Coinbase Pro. The rebranding aimed to distinguish between Coinbase, a user-friendly platform primarily targeted at beginners, and Coinbase Pro, which caters to more experienced and active traders.

2. **Trading Pairs:** GDAX (Coinbase Pro) offered a variety of trading pairs, allowing users to trade cryptocurrencies against fiat currencies (such as USD, EUR, and GBP) and other cryptocurrencies. Popular trading pairs included BTC/USD, ETH/USD, and LTC/USD.

3. **Features:** Coinbase Pro provided features like advanced charting tools, order types (market orders, limit orders, and stop orders), and a more sophisticated trading interface compared to the basic Coinbase platform.

4. **Security Measures:** Like Coinbase, GDAX (Coinbase Pro) implemented robust security measures to safeguard user funds and data. This included two-factor authentication (2FA) and cold storage of a significant portion of user funds.

5. **Integration with Coinbase:** Users with Coinbase accounts could easily transfer funds between their Coinbase and GDAX (Coinbase Pro) accounts, providing a seamless experience for those using both platforms.

6. **API Access:** GDAX (Coinbase Pro) offered API access for algorithmic trading and programmatic access to market data.

It’s important to note that the cryptocurrency industry is dynamic, and changes can occur rapidly. Users interested in the current state of Coinbase Pro or any other cryptocurrency exchange should check the latest information on the official website.