Investing Fundamentals

Stocks vs. Bonds: What Each Does in Your Portfolio

5 min read

Two Engines, Two Jobs

Every balanced portfolio rests on two fundamental asset classes: stocks and bonds. They serve different purposes, respond to different economic forces, and together create a portfolio that's more stable than either would be alone.

Stocks: The Growth Engine

When you buy a stock, you're buying partial ownership in a business. Your return comes from two sources: price appreciation (the stock going up) and dividends (a share of company profits distributed to shareholders).

Historical returns: From 1928 through 2023, US large-cap stocks returned roughly 10% annually before inflation, 7% after. But that average conceals enormous volatility. The S&P 500 has experienced:

A drawdown of 20% or more in roughly 1 out of every 5–6 years
A drawdown of 30%+ in 9 of the past 95 years (about once per decade)
A worst single-year loss of –43.8% (1931) and –38.5% more recently (2008)

Stocks compensate you for this volatility with higher long-term returns—the equity risk premium. Historically, stocks have returned roughly 4–6 percentage points more per year than bonds over long periods.

What drives stock returns: Corporate earnings growth, economic expansion, innovation, productivity gains, and valuation changes (P/E expansion or contraction). Stocks benefit from inflation in the long run because companies can raise prices.

Bonds: The Stabilizer

A bond is a loan you make to a government or corporation. The issuer promises to pay you regular interest (the coupon) and return your principal at maturity.

Historical returns: Investment-grade US bonds have returned roughly 5–6% annually over the long term, with significantly lower volatility than stocks. The worst calendar-year loss for the aggregate bond market (1976–2023) was –13% in 2022—painful but nowhere near a stock market crash.

What bonds do in a portfolio:

Income: Bonds provide predictable interest payments. A 10-year Treasury yielding 4.5% pays $4,500 annually on a $100,000 investment, regardless of what the stock market does.
Diversification: Stocks and bonds are typically, but not always, negatively correlated during equity crashes. In 2008, the S&P 500 fell 37% while the Bloomberg US Aggregate Bond Index gained 5.2%. In 2022, this relationship broke—both fell simultaneously as the Fed raised rates aggressively. The correlation is generally negative but not guaranteed.
Capital preservation: Short-term bonds and Treasuries are the closest thing to a safe asset. When you need money in 2–5 years, it belongs in bonds, not stocks.

When Each Shines

Bonds outperform stocks during recessions, deflationary periods, and flight-to-safety events. In 2000–2002 (dot-com bust), the S&P 500 fell roughly 43% while long-term Treasuries gained over 30%.

Stocks outperform bonds during economic expansions, periods of moderate inflation, and any long-term horizon beyond 10 years. Since 1928, stocks have beaten bonds in every rolling 20-year period.

The Real Risk of Bonds

Bonds have two distinct risks many investors miss:

Interest rate risk: When rates rise, existing bond prices fall. A bond fund with a 7-year duration loses roughly 7% for every 1% increase in rates. This is what crushed bondholders in 2022.
Inflation risk: A bond paying 4% when inflation is 5% loses 1% in real purchasing power annually. That's the silent portfolio killer over multi-decade retirements.

Building the Mix

There's no universal ratio—it depends on your timeline and risk tolerance. The classic 60/40 portfolio (60% stocks, 40% bonds) lost "only" about 21% in 2008 versus 37% for all-stock investors, then recovered within three years with dividend reinvestment. An 80/20 portfolio exposes you to most of the upside with meaningful downside cushioning.