The decision to build a crypto portfolio depends on your investment goals, risk tolerance and knowledge of the crypto market. Forecasting crypto market movements, including potential bear markets, is a very difficult task and no one can predict exactly what will happen in the future. Referring to the 2018 bear market, it should be noted that each market cycle has unique characteristics and is influenced by various factors. So it's important to pay attention to trends, perform fundamental and technical analysis, and weigh the risks as well as the potential rewards when making investment decisions.