What is the 5 3 1 rule in trading?

Excuse me, could you possibly elaborate on the concept of the "5 3 1 rule" in the realm of trading? I'm intrigued to understand how this principle operates and what strategies it advocates for allocating one's investment portfolio. Is it a tactic used specifically in cryptocurrency trading, or does it have broader applications across various financial markets? Furthermore, could you provide some insights into the rationale behind this rule and how it can potentially help traders manage risk and optimize returns?