Asset Allocation: How to Mix Stocks, Bonds, and Cash
The single biggest investment decision isn't picking funds — it's the ratio between them.
Why allocation matters more than fund picking
Research consistently shows that asset allocation — the split between stocks, bonds, and cash — explains the majority of long-term portfolio performance differences. Fund selection within each category matters far less than getting the mix right.
Stocks: growth, volatility
Stocks have historically delivered the highest long-term returns but with wide swings year-to-year. A 30–40% drop in a bad year is normal. The longer your horizon, the more stocks you can comfortably hold.
Bonds: stability, lower returns
Bonds typically return less than stocks but with much smaller swings. They serve two roles: dampening portfolio volatility, and providing dry powder to rebalance into stocks during downturns.
Cash: liquidity, no growth
Cash protects against forced selling but loses purchasing power to inflation. Hold enough to cover known short-term needs and emergencies; not more.
Rules of thumb for the mix
A common starting point is '110 minus your age' as a stock percentage. A 30-year-old: 80% stocks, 20% bonds. A 60-year-old: 50/50. Adjust based on your comfort with volatility and your specific timeline.
Rebalance once a year
When stocks rise faster than bonds, your allocation drifts. Once a year (or when any category drifts 5%+ off target), sell some of the overgrown category and buy the underweight one. This forces 'buy low, sell high' automatically.
Frequently asked questions
Should I include international stocks?
Most experts recommend 20–40% of your stock allocation in international markets for diversification.
What about real estate and gold?
Both are reasonable small additions (5–15% combined) for diversification but not essential to a working portfolio.
Are target-date funds a good shortcut?
Yes — they handle allocation and rebalancing automatically, glide more conservative over time, and are excellent default choices for retirement accounts.