Asset Allocation for Beginners: How to Pick Your Stock and Bond Mix
Asset allocation is how you split your money between stocks, bonds and cash. It is the biggest decision you make as an investor, bigger than which fund you pick, because it sets both how much you can expect to earn and how much you can lose in a bad year. This guide shows what each mix actually did over 153 years of U.S. market history, then how to pick yours.
The Short Answer
- More stocks = higher long-run return and deeper losses. From 1871 to 2023, an all-stock portfolio grew about 6.9% a year after inflation but lost 38% in its worst year; 60% stocks and 40% bonds grew about 5.5% a year and lost 25% in its worst year.
- Money you need within about five years belongs mostly in cash and short-term bonds, not stocks.
- Money for 10+ years can hold mostly stocks, if you can sit through a 30% to 50% drop without selling.
- The simplest way to hold a mix is one target-date or balanced fund, or two or three broad index funds.
- Rebalance about once a year so the mix does not drift toward more risk than you chose.
What Asset Allocation Is
Different investments respond differently to the same events. Stocks tend to do well when the economy grows and badly in recessions. High-quality bonds often hold up or rise when stocks fall, though not always (2022 was an exception, when both fell). Cash barely moves at all. Holding a mix means one part can cushion another, so the whole portfolio swings less than its riskiest piece.
Allocation is about proportions, not picks: "70% stocks, 25% bonds, 5% cash" is an allocation. Which stock fund fills the 70% is a separate, smaller decision.
What Each Mix Did, 1871 to 2023
We ran every mix from all stocks to all bonds through 153 years of U.S. data, rebalancing back to the target each January. All figures are real, meaning after inflation, so they show what happened to purchasing power.
| Stocks / bonds | Average annual real return | Worst single year | Worst 10-year stretch (per year) | Years with a loss |
|---|---|---|---|---|
| 100 / 0 | 6.95% | −38.0% (1931) | −4.4% (1999 to 2008) | 46 of 153 |
| 80 / 20 | 6.31% | −28.5% (1917) | −3.6% (1911 to 1920) | 48 of 153 |
| 60 / 40 | 5.54% | −25.2% (1917) | −3.5% (1911 to 1920) | 45 of 153 |
| 40 / 60 | 4.63% | −21.8% (1917) | −3.7% (1972 to 1981) | 49 of 153 |
| 20 / 80 | 3.60% | −18.4% (1917) | −4.3% (1972 to 1981) | 43 of 153 |
| 0 / 100 | 2.44% | −17.2% (2022) | −5.0% (1972 to 1981) | 54 of 153 |
Three things in this table surprise most beginners:
- All bonds was not the safe choice. It had the lowest return and the most losing years, and inflation in the 1970s gave it the worst decade of any mix. Bonds are steadier from year to year, not immune to inflation.
- Every mix had a lost decade. Even 60/40 lost purchasing power over a full ten years. That is why money you need soon should not depend on markets at all.
- A little bond goes a long way. Going from 100% to 80% stocks cut the worst year by almost 10 percentage points while giving up only about 0.6 points of average yearly return.
Annual data also hides losses within a year. The stock market's falls from peak to bottom were often deeper than any single January-to-January number shows, so expect a 100% stock portfolio to drop by half at some point in a long investing life.
The Building Blocks
| Asset | Role in a portfolio | Main risk | Simple way to hold it |
|---|---|---|---|
| U.S. stocks | Long-run growth | Large, sudden drops | Total-market or S&P 500 index fund |
| International stocks | Growth from the rest of the world; spreads country risk | Currency swings, long stretches of lagging the U.S. | Total international index fund |
| High-quality bonds | Steadier returns, often a cushion in stock crashes | Rising interest rates and inflation | Total bond market or Treasury index fund |
| Cash | Spending money and emergencies | Inflation slowly eats it | High-yield savings or money market fund |
| Real estate, commodities, crypto | Optional extras | Volatile; some (crypto) have very short histories | Keep small, if at all |
A broad index fund already spreads money across hundreds or thousands of companies, so most of the diversification work is done by holding the right two or three funds. Our ETF vs index fund guide explains the fund types.
How to Choose Your Mix
Work through three questions, in this order.
- When do you need the money? Under about 5 years: mostly cash and short-term bonds. 5 to 10 years: a balanced mix. More than 10 years: you can afford mostly stocks. Split your money by goal; a house deposit and a retirement account deserve different mixes.
- How much can you afford to lose? If a drop would force you to sell (because you have no emergency fund, or need the money for living costs), you need less in stocks regardless of age. A stable job, other savings and a pension or Social Security all raise how much risk you can carry.
- How much can you stand to watch fall? Look at the worst-year column above and picture it in dollars. If you hold $50,000 at 80% stocks, a 28% year means watching about $14,000 disappear. If that would make you sell at the bottom, choose a lower stock share; the mix you stick with beats the "better" mix you abandon. Our guide to assessing your risk tolerance goes further.
| Situation | Starting point to consider |
|---|---|
| Long horizon, steady income, can ignore big drops | 80 to 90% stocks |
| Long horizon, nervous about losses | 60 to 70% stocks |
| Within 10 years of retirement | 40 to 60% stocks, plus several years of spending in cash or short bonds as retirement nears |
| Money needed within 5 years | 0 to 20% stocks |
Our retirement calculator lets you try different stock shares against every historical period since 1871 and see how often the money would have lasted.
Example: Putting a 60/40 Mix Into Practice
Hypothetical example for illustration. Someone with $20,000 to invest for retirement chooses 60% stocks and 40% bonds:
| Fund | Target | Amount |
|---|---|---|
| U.S. total stock market index fund | 45% | $9,000 |
| International stock index fund | 15% | $3,000 |
| Total U.S. bond market index fund | 40% | $8,000 |
A year later stocks have risen 20% and bonds 2%. The stock funds are now worth $14,400 and the bond fund $8,160, so the mix has drifted to about 64% stocks and 36% bonds. To get back to 60/40 on the new $22,560 total, the investor moves about $860 from the stock funds to the bond fund (60% of $22,560 is $13,536 in stocks), or simply directs new contributions to bonds until the mix is back.
The one-fund alternative is a target-date fund or a balanced fund, which holds a similar mix and rebalances automatically.
Keeping the Mix on Target
Markets move your allocation for you. After a long stock rally, a 60/40 portfolio can quietly become 75/25, carrying more risk than you chose. Rebalancing means bringing it back:
- On a schedule: once a year is enough for most people.
- Or by threshold: when any part is more than about 5 percentage points off target.
- Cheapest way: send new contributions to whichever part is underweight, so you rarely have to sell.
- Taxes: rebalance inside 401(k)s and IRAs where possible; selling in a taxable account can trigger capital gains tax.
Our rebalancing guide covers how often, and the trade-offs, in more detail.
Changing the Mix Over Your Life
As the date you need the money gets closer, you have less time to recover from a crash, so most plans move gradually from stocks toward bonds and cash. Target-date funds do this automatically along a set "glide path". If you manage it yourself, change the mix in planned steps (for example every five years), not in reaction to the news. In retirement, many people keep a few years of spending in cash and short-term bonds so they never have to sell stocks in a downturn.
Common Mistakes
- Changing the mix after a crash. Selling stocks after they fall locks in the loss and usually misses the recovery.
- Too little in stocks for long-term money. Over decades, a very cautious mix can lose ground to inflation, as the all-bond row shows.
- Counting the same thing twice. Owning five U.S. stock funds is not diversification if they hold the same large companies.
- Ignoring the whole picture. Your 401(k), IRA and taxable accounts together are one portfolio; set the mix across all of them.
- No emergency fund. Without cash set aside, a job loss can force you to sell investments at the worst time.
- High fees. A 1% yearly fee takes a large share of a 5% real return. Broad index funds often cost under 0.1%.
FAQ
What is a good asset allocation for a beginner?
It depends on when you need the money. For retirement savings decades away, many beginners hold 70 to 90% in stock index funds and the rest in bonds. For money needed within five years, mostly cash and short-term bonds. A target-date fund is a simple one-fund option.
What did a 60/40 portfolio return historically?
In our calculation from Shiller's data for 1871 to 2023, a 60% stock and 40% bond mix rebalanced each year grew about 5.5% a year after inflation, with a worst single year of −25.2% (1917).
Are bonds safer than stocks?
Year to year, yes: in the same data, an all-bond portfolio's worst year was −17.2% (2022) versus −38.0% for stocks (1931). Over long periods bonds are vulnerable to inflation, and an all-bond portfolio had the worst ten-year stretch of any mix, during 1972 to 1981.
How often should I rebalance?
Once a year, or whenever a part of your portfolio drifts more than about 5 percentage points from its target. Using new contributions to rebalance avoids selling.
Should I use the "110 minus your age" rule?
It is a rough starting point for the stock share (a 30-year-old would hold 80% stocks), not a rule. Your time horizon, job stability and how you react to losses matter more than your age alone.
Does asset allocation matter in a 401(k)?
Yes. It is where most people's largest investments are. Many plans default to a target-date fund, which sets the allocation for you; check that its date matches when you expect to retire.
Educational content, not personal investment advice. Historical figures are our own calculations from public data and do not predict future returns.
