Stocks make you money. Bonds keep you in the game. The split between the two is the single biggest decision in your portfolio.
What Each One Does
Stocks are ownership in businesses. Over long periods (15+ years) they have returned about 10% nominally in the US. Year to year they can swing −40% to +40%.
Bonds are loans to governments and companies. They return a modest 3–5%, but the rides are far smoother. In severe stock crashes, bonds often rise.
The Trade-Off
More stocks = higher long-term return, bumpier ride, larger drawdowns. More bonds = lower long-term return, smoother ride, smaller drawdowns.
The "right" mix depends on three things: how long until you need the money, how much volatility you can tolerate emotionally, and how stable your income is.
Common Mixes
- 20s–30s: 80–90% stocks, 10–20% bonds.
- 40s: 70% stocks, 30% bonds.
- 50s: 60/40 — the classic balanced portfolio.
- Retirement: 50/50 or 40/60, plus 1–2 years of expenses in cash.
A rough rule of thumb: stock allocation = 110 − age. Adjust up if you have a stable pension; down if your career income is volatile.
Why the Split Matters
In 2008, a 100% stock portfolio dropped 50%+. A 60/40 portfolio dropped ~28% — still painful but survivable. Survivability is the whole point of bonds for long-term investors.
Within Bonds
A simple total-bond-market fund gives you Treasuries plus high-grade corporates. Layer in TIPS for inflation protection and short-term Treasuries for cash-like stability if you want more nuance. Use our Bond Yield Calculator to compute current yield and YTM on any specific bond.
Within Stocks
For most US investors: 70% US, 30% international. Use total-market index funds for both.
Rebalance Annually
Drift is the enemy. Once a year, run our Portfolio Rebalancing Calculator to bring everything back to target.
Bottom Line
Pick a stock/bond mix that matches your age and risk tolerance. Stay invested through downturns. Rebalance once a year. That is the entire long-term plan.
Frequently Asked Questions
What roles do stocks and bonds each play in a portfolio?
Stocks are generally the primary driver of long-term growth, having returned roughly 10% nominally per year in the U.S. over long periods, though with significant year-to-year swings. Bonds typically return a more modest 3–5% but provide much greater stability and often hold up or even rise during severe stock market declines, which helps investors stay invested during downturns. The combination is intended to balance growth potential against the ability to endure market stress.
How much of a portfolio should be in stocks versus bonds?
A common rule of thumb is that stock allocation should roughly equal 110 minus your age, so a 30-year-old might target around 80% stocks and a 60-year-old around 50%, though this should be adjusted for individual risk tolerance and income stability. Retirees often hold 40–50% stocks along with 1–2 years of cash for near-term expenses. This is a general starting framework, not personalized financial advice.
How much did a 100% stock portfolio lose in 2008 compared to a balanced portfolio?
During the 2008 financial crisis, a portfolio fully invested in stocks dropped more than 50%, while a 60/40 stock/bond portfolio declined by roughly 28% — still a painful loss, but generally considered more survivable. This illustrates the core purpose of holding bonds: not to maximize returns, but to limit the depth of drawdowns so investors are less likely to panic-sell at the bottom. Past crisis performance is informative but not a guarantee of how future downturns will unfold.
Run the numbers yourself
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