Cryptocurrencies have become a popular form of investment in recent years, with a few coins standing out in terms of purchase volume and popularity.

1. **Bitcoin (BTC)**: As the first cryptocurrency, Bitcoin is often seen as the “go-to coin,” and many new investors buy BTC as a way to gain exposure to the cryptocurrency market. Its scarcity, with a limit of 21 million coins, and growing acceptance in businesses contribute to its popularity.

2. **Ethereum (ETH)**: Ethereum is the second most purchased cryptocurrency. Its smart contract platform enables the creation of a wide range of dApps and services, making it an attractive choice for investors who are betting on technological innovation.

3. **Binance Coin (BNB)**: BNB, the native coin of the Binance exchange, is widely purchased due to its utility on the platform. Users buy BNB to pay discounted trading fees and participate in new token launches, which increases its adoption.

4. **Cardano (ADA)**: Cardano, known for its focus on research and development, has been attracting the attention of developers and investors alike. With its ever-expanding capabilities, many consider ADA to be a promising option, resulting in high buying volume.

5. **Ripple (XRP)**: Despite facing some legal controversies, XRP continues to be one of the most purchased cryptocurrencies, especially among those who believe in its ability to facilitate fast and efficient cross-border transactions.

These cryptocurrencies not only represent investment opportunities but also reflect the growing confidence in the digital finance space. However, it is always important to do your own research and consider the associated risks before investing.