All investments have an inherent risk. Typically there is a direct relationship between risk and return. The more risky an investment is the higher the return investors demand. Thus, when considering an investment, a key question to ask is whether the expected return on the investment is commensurate with the risk that this particular investment entails. This is called a mean-variance analysis, and before investing in BTC, or in the stock market for that matter, you should probably do exactly that kind of analysis.