Asset allocation & choosing a mix

Asset allocation is how a portfolio is divided among broad asset classes, such as stocks, bonds, and cash. Stocks have historically offered higher long-run growth potential with substantial volatility; high-quality bonds can provide income and behave differently, but they carry interest-rate, credit, inflation, and liquidity risks. Cash can serve near-term needs while offering little long-term growth potential after inflation in some environments.

The mix you choose affects how much a portfolio may fluctuate, but the exact outcome is unknowable. Rules like “100 minus your age” are oversimplifications: they ignore goal timing, pensions, debt, income stability, account types, other assets, and how you behave during declines.

Separate a goal's near-term spending reserve from its long-term growth pool. For a goal with a fixed near date, a large loss just before spending is especially harmful; for a flexible goal decades away, there may be more room to tolerate market swings. A longer horizon helps only if you have the liquidity and discipline to stay invested.

Estimate a downside scenario, not just an average-return scenario. Ask how the plan behaves through a prolonged stock decline, a rise in rates that hurts bonds, higher-than-expected inflation, or a loss of income. If the plan only works under optimistic assumptions, revisit the savings rate, goal date, or risk level.

An allocation range can give you a trigger for review without pretending to know which asset will lead next. Decide the target and acceptable drift while calm. Use consistent definitions for the holdings, and account for bonds of different credit quality, inflation-linked bonds, and cash as distinct exposures when relevant.