When it comes to saving for retirement, deciding how much of your paycheck to set aside is often the first thing people focus on, and rightfully so. But just as important, and often overlooked, is deciding how that money will be invested through proper asset allocation.
Many savers spend significant time thinking about contribution amounts but very little time considering their asset allocation strategy. Yet, how your savings are allocated can have just as much, if not more, impact on your long-term retirement outcome than the actual dollar amount you contribute each pay period.
Understanding the basics of asset allocation will help you make better investment decisions, avoid common pitfalls, and recognize when professional guidance can put you on the right path to a successful financial future.
What Is Asset Allocation and Why Is It Important?
Asset allocation refers to the breakdown of investments among various asset classes such as stocks, bonds, and cash to balance risk and reward.
At its core, asset allocation is expressed as a percentage split, usually between stocks and more stable assets such as bonds, annuities, and cash. For instance, a portfolio with 60% invested in stocks and 40% in bonds is described as having a “60/40 allocation.” Similarly, a portfolio consisting of 80% stocks and 20% bonds is called an “80/20” allocation. These ratios offer a quick snapshot of whether a portfolio is positioned more aggressively or conservatively.
The Power of a 60/40 Allocation Strategy
The 60/40 portfolio has long operated as the most popular benchmark for moderate investment strategies. This split seeks to balance two often-competing goals: maximizing growth and minimizing volatility. Within this framework, portfolios with more than 60% allocated to stocks are considered to be more aggressive, while those with lower stock allocations are viewed as more conservative.
Comparing Stocks, Bonds, and the 60/40 Portfolio
Historical Performance of Stocks and Bonds
Stocks and bonds have historically complemented each other. Stocks usually deliver higher returns over the long run, though stocks can be more unpredictable in the short term. Bonds, on the other hand, generally provide steadier returns with less risk. These two types of investments often move in different directions. When stocks decline, bonds may rise or remain stable. This balance helps reduce overall portfolio volatility and is supported by decades of real-world performance data.
The chart above illustrates the best and worst returns for three different portfolios (one invested entirely in stocks, one entirely in bonds, and one with a 60/40 mix of stocks and bonds) over rolling periods of one, five, ten, and twenty years. A “rolling period” refers to every possible sequence of consecutive years within a given timeframe (for example, 1950–1954, 1951–1955, and 1952–1956 are all five-year rolling periods).
Why Stocks Are Riskier in the Short Term
Since 1950, the best single year for stocks (represented by the green bar for the S&P 500/C-Fund) saw a remarkable 52% gain, while the worst year experienced a 37% loss. This wide range of possible outcomes, including significant double-digit declines, highlights why advisors typically caution against using stocks for short-term goals. Whether you’re saving for an upcoming house down payment or are nearing retirement and planning to take regular distributions for living expenses, it’s important to consider investments with more stability during these critical periods.
How Bonds Provide Stability
With bonds (the blue bar, representing the Bloomberg Aggregate/F-Fund), which are generally a less volatile option, we see the expected pattern. A lower peak gain of 33% but also a smaller drop, with the worst year at -13%. While bonds tend to be more stable than stocks, they can still experience negative returns. For example, during periods of rising interest rates, like in 2022 when the Federal Reserve increased rates to fight inflation, the value of existing bonds often declines.
The Balanced Advantage of the 60/40 Portfolio
The gray bar represents the highs and lows of a 60/40 portfolio. The advantages of this balanced approach become even clearer when looking at five-year rolling returns. During the worst five-year stretches, both the all-stock and all-bond portfolios averaged an annual return of -2%. In contrast, from 1950 through the end of 2024, there has never been a five-year period in which the 60/40 portfolio lost money. For a 100% stock portfolio, you have to look out as far as 20-year periods before seeing no losses. Over the long run, the 60/40 portfolio’s average annual returns trail those of an all-stock portfolio by about 2%, but in return, it offers a meaningful reduction in short-term ups and downs.
It’s important to note, however, that the 60/40 split isn’t a magic formula. It doesn’t guarantee the highest possible returns or protect completely against market downturns. Instead, it serves as a middle ground, a common reference point to evaluate whether your investment strategy leans more toward growth or stability.
Choosing the Right Allocation for Your Needs
Understanding Risk Tolerance and Capacity
An optimal asset allocation accounts for your risk tolerance (how much market fluctuation you can emotionally handle) and your risk capacity (how much loss your financial situation can absorb). It is also important to consider the timing of your investment goals for the funds in question. Money you will need to use relatively soon should be invested very differently from money you plan to leave as an inheritance 30 years from now.
Setting a Target Allocation
Once you have decided on a broad asset allocation, there are still important decisions to be made to ensure your portfolio is set up properly. If a 60/40 portfolio is right for your financial plan, you still need to determine the specific types of investments you will make to reach that target allocation.
Selecting Asset Classes
Diversifying Your Stock Allocation
When building your portfolio, it’s not just about choosing between stocks and bonds. It’s about thoughtfully selecting the types of each to include. As shown in the asset allocation chart below, often called a “quilt chart” due to its colorful, shifting patterns, there are many sub-categories within both stocks and bonds that perform differently over time. Diversifying across these sub-classes can help create a more balanced investment experience and reduce volatility. The sections below outline how to think about setting both your stock and bond allocations with this broader perspective in mind.
Stock Allocation Within the Thrift Savings Plan
Within the Thrift Savings Plan, you have access to several major equity categories through the C, S, and I Funds. However, many other sub-classes, such as emerging markets, real estate (REITs), and sector-specific funds, are only available outside the TSP. Your exposure is restricted to 500 U.S.-based companies if you only use a stock like the S&P 500. As the quilt chart illustrates, including a wider range of equity investments can help smooth returns over time and reduce concentrated risk.
Bond Allocation Beyond the Basics
The TSP’s F Fund offers broad exposure to the U.S. bond market, but it doesn’t capture the entire landscape. Segments such as high-yield bonds, international debt, and inflation-protected securities fall outside its scope. For retirees or those nearing retirement, incorporating strategies such as fixed index annuities can also help strengthen the conservative side of the portfolio by offering potential downside protection and more consistent returns.
The “Final” Decision on Asset Allocation
An Ongoing Process, Not a One-Time Choice
Setting an appropriate asset allocation means balancing a range of factors: your short- and long-term goals, risk tolerance and capacity, and the broader economic environment. What makes this especially challenging is that these factors are constantly in flux. They shift as your life evolves. That’s why asset allocation isn’t a one-time decision. It’s an ongoing process that requires regular review and adjustment.
The Importance of a Financial Advisor Partnership
Partnering with a financial advisor can help ensure your investment strategy reflects your current circumstances and adapts as your needs change. With a personalized, flexible approach, you’ll be better prepared to weather market ups and downs and stay on track for a secure and fulfilling retirement.
