Why not just put everything into one asset?
Concentrating in a single asset means your entire portfolio moves exactly in step with that asset's price -- for better or worse. Spreading investments across several assets means that if one falls, the others can offset at least part of that decline, which is the basic logic behind diversification rather than a guarantee against loss.
A few common starting frameworks
There's no single correct ratio, but several rough starting points are commonly discussed: a 60/40 split between stocks and bonds as a classic moderate benchmark, or an age-based rule of thumb that scales your bond allocation up as you get older. These are starting points for a conversation with a financial professional, not a formula to apply blindly to your own situation.
Frequently Asked Questions
Is asset allocation something you set once and leave alone?
No -- price movements over time shift your ratios away from the original target, so periodically reviewing your allocation and rebalancing when needed is standard practice.
Is a higher share of risk assets always better?
Not necessarily. The right balance depends on your own time horizon, goals, and tolerance for risk, and it can look very different from one person to the next.