Asset allocation frameworks — the 80% decision.

Why allocation dominates returns

Brinson, Hood, and Beebower's landmark 1986 study (and replication studies since) consistently find that asset allocation explains 80-91% of the variation in portfolio returns over time, with security selection and market timing explaining the remainder. The practical implication: getting your allocation right matters far more than picking the right individual securities within an allocation.

Classic frameworks

60/40 (equity/fixed-income). The traditional "balanced" portfolio, designed for moderate growth with material downside protection. Effective for accumulators with 10-30 year horizons. Has had a difficult decade in the post-2008 low-rate environment but remains a foundational reference framework.

Three-fund portfolio (total US equity / total international equity / total bond). Maximum simplicity, low cost, broad diversification. Often used by passive-investing purists. Works well for accumulators with a single time horizon; less optimal for HNW clients with multiple time horizons (current spending, near-term liquidity, long-term legacy).

Target-date glide path. Allocation that automatically becomes more conservative as a target date (typically retirement) approaches. Useful for 401(k) participants without a personalized strategy; less appropriate for HNW clients with custom income, tax, and legacy considerations.

HNW-specific allocation considerations

For HNW investors, the right allocation often isn't a single percentage — it's a tiered structure that reflects multiple time horizons within the same household balance sheet:

• Operating cash tier: 6-24 months of spending in highly liquid, short-duration instruments
• Near-term goals tier: 1-5 year horizons (real estate, education, major purchases) in shorter-duration fixed income
• Core retirement/income tier: 10-25 year horizon in a diversified balanced allocation
• Legacy tier: 25+ year intergenerational horizon, often more growth-oriented than the income tier would suggest

Each tier deserves its own allocation — and a single household number obscures more than it reveals.

Rebalancing discipline

Most of the value of a defined allocation comes from the discipline of rebalancing back to it when markets push it out of alignment. Annual or tolerance-band-triggered rebalancing forces a "sell high / buy low" discipline most investors find emotionally difficult to do on their own.

See Diversification Strategies for the related topic of WHAT to diversify across.