How to invest $15,000 usd?

In the current crypto and financial landscape, how should one approach investing $15,000 USD? What factors should be considered? Is it advisable to invest the entire amount in a single asset or should it be diversified? What percentage of the total should be allocated to cryptocurrencies, traditional stocks, bonds, or other investment vehicles? What are the risks associated with each investment option? Are there any specific strategies or guidelines one should follow to maximize returns while minimizing risks? Additionally, how often should the investments be reviewed and rebalanced to ensure optimal performance?