Diversification and asset allocation: three-fund, 60/40, all-weather and more

Diversification

It is the oldest advice in investing: do not put all your eggs in one basket. Holdings that behave differently from each other smooth out the ride. It does not remove risk, and in a severe market fall most stocks drop together, but it limits the damage from any single company, sector or country going wrong.

How many holdings?

There is no magic number. Studies suggest much of the single-company risk disappears across a few dozen stocks in different industries, and one broad fund can hold thousands. What matters more than the count is how much each one weighs and how related they are.

Asset allocation

This is your split across asset classes: stocks, bonds, cash, and sometimes real estate, gold or others. It is usually the largest driver of how your portfolio behaves, more than which individual stocks you picked.

Famous templates

• 60/40: 60% stocks, 40% bonds. A long-time classic for balancing growth and stability.
• Three-fund portfolio: a total US stock fund, a total international stock fund and a total bond fund. Popular among followers of John Bogle, the “Bogleheads”.
• All-weather: a mix designed to hold up in different economic environments (growth, recession, inflation, deflation), typically using stocks, long and intermediate bonds, gold and commodities.
• Risk parity: weights assets by how much risk they contribute, not by dollars, and sometimes uses leverage.
• Core-satellite: a diversified low-cost core (often index funds) plus a small “satellite” of individual picks or themes.

Each has trade-offs and none is guaranteed to outperform. Treat them as a way to see how others structure risk.

Rebalancing

Over time winners grow and your mix drifts. Rebalancing means bringing it back to target, either on a schedule or when it drifts by a set amount. See our rebalancing guide for how to do it without unnecessary costs.

Active or passive?

Passive investing tracks an index at low cost. Active investing tries to beat it through selection or timing. Many people use passive funds as the base and keep active choices small, so a mistake there cannot sink the whole plan.

Build the portfolio you can hold through a 30% fall. The best allocation on paper is useless if you abandon it.