Last month, 28-year-old Lila sat across from me with a notebook full of scribbled questions: She’d saved $15,000 from her job as a graphic designer and wanted to invest, but the idea of putting “too much” in stocks made her nervous. “What if the market crashes and I lose it all?” she asked, twisting a pen. A few weeks later, 55-year-old Mike, a high school teacher, had the opposite worry: He’d kept most of his savings in a savings account for decades, and now he wondered if he’d have enough for retirement. “I never knew how to split my money,” he said. “I just played it safe—and now I’m scared it’s not enough.”
Lila and Mike are facing the same core challenge: asset allocation, or how to divide your investments across different assets (like stocks, bonds, and cash) to balance risk and growth. It’s a concept that sounds abstract, but it’s really about matching your money to your life—your age, your goals, and how much uncertainty you can live with. The simplest way to start, especially for anyone new to this, is the “110-age rule”—a guideline that turns your birth year into a clear, actionable plan.
Here’s how it works: Subtract your age from 110. The result is the percentage of your investment portfolio that could go into stocks (which tend to offer higher long-term growth but more short-term volatility). The rest goes into more stable assets, like bonds (loans to governments or corporations that pay regular interest) or cash. For Lila, 110 minus 28 is 82—so roughly 82% of her $15,000 could be in stocks, and 18% in bonds or cash. For Mike, 110 minus 55 is 55—so 55% in stocks, 45% in bonds or cash. The logic is simple: Younger people have more time to ride out market dips. If stocks fall when Lila is 28, she has 30+ years to wait for them to recover and grow. Mike, with 10 years until retirement, can’t afford to wait out a big crash—so he needs more stability.
Let’s ground this in real life. When Lila heard the 82% number, she blinked. “That seems like a lot,” she said. I explained that stocks aren’t just “gambling”—over the past 70 years, the S&P 500 (an index of 500 large U.S. companies) has delivered an average annual return of about 10% (adjusted for inflation). But yes, there will be down years—like 2022, when the S&P 500 fell 19%. For Lila, though, a 19% drop in her 20s isn’t a disaster; by the time she’s 35, that dip could be a blip in her portfolio’s growth. Mike, by contrast, couldn’t afford a 19% drop in his 50s—he might need to start withdrawing money in a few years, so he needs assets that won’t swing as much. Bonds, for example, have historically been less volatile: During 2022, while stocks fell 19%, U.S. Treasury bonds fell about 13%—a smaller hit, and they still paid regular interest.
The 110-age rule isn’t perfect, of course—it’s a starting point, not a one-size-fits-all solution. If Lila hated the idea of watching her portfolio drop even 10%, she could tweak the number: Maybe 75% stocks, 25% bonds. If Mike was comfortable with a little more risk (and had other savings), he could go to 60% stocks. The key is that it gives you a framework to build on—something better than guessing or following a friend’s advice.
I checked in with Lila last week. She’d split her $15,000 into 80% stocks (mostly low-cost index funds, which track the market) and 20% bonds. “I still check my portfolio once a week,” she said, “but I don’t panic when it goes down. I remember I have time.” Mike, meanwhile, moved 50% of his savings into a mix of stocks and bonds—enough growth to boost his retirement fund, but enough stability to sleep at night. “It feels like I finally have a plan,” he said.
Asset allocation isn’t about picking “winning” stocks or timing the market. It’s about understanding your place in life—and making your money work with you, not against you. The 110-age rule turns a scary, abstract concept into something you can write down in your planner: a number that’s tied to how old you are, and how much time you have. For Lila and Mike, that’s been the difference between feeling lost and feeling in control. And isn’t that what we all want from our money?
