Bitcoin, the largest cryptocurrency in the world by market cap, has delivered dismal returns for investors over the past year or so. Since peaking at nearly $20,000 in December 2017, bitcoin has lost more than 82% of its value. However, there's still a valid long-term investment case to be made. There are still experts who believe that bitcoin will be adopted as a currency on a wide-scale, and others say that it could become a widely used store of value, similar to gold.