Bitcoin is having a wild ride in 2018.
The digital currency began the year on high note. Bitcoin prices nearly reached $20,000 in December 2017 as investors poured into cryptocurrencies.
But as this year went on, the crypto craze faded. By June, bitcoin prices were under $6,000. To the crypto-faithful, however, the revolutionary promise of digital currencies still looms large. Here's what they had to tell CNBC about the future of bitcoin and cryptocurrencies.