What is the safest asset to buy?

Excuse me, I've been hearing a lot about cryptocurrencies and financial investments, but I'm still quite confused about which asset is the safest to buy. Given the volatile nature of the market and the various risks involved, could you please elaborate on what you consider the most secure option? I'm looking for something that offers stability and long-term growth potential. Also, I'd appreciate it if you could provide some insights into how to evaluate and diversify my portfolio effectively. Thank you in advance for your expert advice.