You set up your 401(k) years ago. You picked an allocation that felt right. You automated contributions. And then, like most Americans, you forgot about it.

That single habit—setting and forgetting—may be costing you more than you realize.

According to retirement plan data from Alight Solutions, the average 401(k) investor maintained a steady 73.5% equity exposure throughout early 2026. That number looks reassuring until you ask one crucial question: Is that the allocation you actually intended?

For many investors, the answer is no. Market movements have silently reshaped their portfolios, creating a risk profile they never agreed to. Here’s how to spot the signal that it’s time to act—and what to do about it.

The Signal: When Your Portfolio No Longer Looks Like You

The most critical signal that it’s time to rebalance is simple: your current asset allocation no longer matches your target allocation.

This happens naturally. When certain assets perform well, they grow to represent a larger share of your portfolio than you originally intended. When others underperform, they shrink in relative importance.

Industry experts call this “asset allocation drift,” and it’s one of the most common—and most overlooked—mistakes in retirement investing.

Here’s how it works. Imagine you started with a simple 60% stock / 40% bond allocation. After several strong years in the equity market, your portfolio might now look more like 75% stocks and 25% bonds. You didn’t choose to take on more risk. The market chose it for you.

The problem isn’t that stocks performed well—it’s that your portfolio now behaves differently than planned. When the next downturn arrives, your losses will be larger than expected, not because you made a bad investment decision, but because you let a silent drift go uncorrected.

As PortfolioPilot’s retirement analysis notes: “The portfolio you end up with may no longer resemble the one you agreed to hold. This is where risk changes without consent”.

Why 401(k) Accounts Are Especially Vulnerable

Retirement accounts are designed for long-term holding. That’s a strength—but it also creates blind spots. Because 401(k)s and IRAs are tax-advantaged, there’s no immediate tax signal when allocations drift. Statements emphasize balances, not risk composition. And years can pass without a meaningful review.

The data from February 2026 confirms this pattern. According to the Alight Solutions 401(k) Index, participants showed remarkable calm during market volatility, with trading activity remaining light—just 0.013% of balances transferred daily. While this reflects disciplined long-term thinking, it also means many investors may not be checking their allocations as often as they should.

The most telling detail? International and emerging market funds captured more than half of all trading inflows in February, while large U.S. equity funds saw concentrated outflows. This suggests that the investors who were paying attention recognized they had become overweight in domestic large-cap stocks and made surgical adjustments to rebalance toward geographic diversification.

The Cost of Ignoring the Signal

Failing to rebalance isn’t about fine-tuning performance—it’s about maintaining the risk profile you originally chose.

Consider the long-term impact. A portfolio that drifts toward higher equity exposure will experience greater sensitivity to market downturns. In a bear market, the losses will be more severe than you anticipated. In a bull market, you may feel like a genius—until the cycle turns.

The risk is particularly acute for investors approaching retirement. As Morningstar’s retirement planning guidance emphasizes, those in their 60s should consider not just portfolio returns but also the psychological comfort of knowing their risk exposure matches their stage of life.

“If your retirement numbers are in relatively good shape, you can afford to put more weight on financial decisions that give you peace of mind and even a bit more joy,” Morningstar notes. Rebalancing is one of those decisions—it restores intention and eliminates the hidden stress of unknowingly holding more risk than you intended.

How to Spot the Signal in Your Account

So how do you know if your portfolio has drifted? Here are three concrete signs:

1. You Haven’t Reviewed Your Allocation in Over a Year

If you can’t remember the last time you checked your 401(k) asset allocation, it’s time to look. The SECURE 2.0 Act has introduced new rules for 2026, including catch-up contribution requirements for high earners and higher contribution limits across the board. A review is overdue.

2. Your Largest Holding Has Grown Disproportionately

Log into your account and look at the percentage breakdown. If one fund—say, a large-cap U.S. equity fund—now represents significantly more of your portfolio than it did when you set it up, you’ve experienced drift.

3. You’re Relying on a Target Date Fund Without Understanding Its Allocation

Target date funds are the workhorse of many 401(k) plans, representing 31% of total balances and capturing the largest share of new contributions in early 2026. But as Nasdaq’s analysis points out, these funds have two drawbacks: they tend to err on the side of being too conservative overall, and they often come with higher fees.

If you’re in a target date fund, the signal to act isn’t necessarily to abandon it—it’s to understand what allocation it’s actually giving you and whether that matches your goals.

What to Do When You See the Signal

If you’ve spotted the signal, here’s how to respond:

1. Determine Your Target Allocation

Start with your goals and timeline. A common rule of thumb: subtract your age from 110 to get a rough equity percentage target. But your actual target should reflect your risk tolerance, not just a formula.

2. Compare Current vs. Target

Calculate your current allocation across major categories: U.S. stocks, international stocks, bonds, and cash or stable value funds. If any category is off by more than 5 percentage points, rebalancing is warranted.

3. Execute the Rebalance

Most 401(k) plans allow you to rebalance online in minutes. You can either:

Transfer existing balances: Move money from overweight categories to underweight ones.
Redirect new contributions: Adjust where your future contributions go to gradually correct the drift.

4. Set a Schedule

Plan to review your allocation at least annually. Some investors prefer quarterly check-ins; others use threshold-based rebalancing—acting only when an allocation drifts beyond a set range (e.g., 5% off target).

As Morningstar’s purposeful investor resolutions for 2026 advise: “Shift your focus from saving to fine-tuning. It’s about identifying the friction points—taxes, cash drag, and risk—and making adjustments to improve your aftertax, after-inflation outcome”.

A Note on Target Date Funds

If you’re in a target date fund, the decision is different. These funds rebalance automatically, so you don’t need to manage individual allocations. But that doesn’t mean you can ignore them entirely.

According to Nasdaq’s analysis, target date funds often invest too conservatively, which can limit growth over time. And fees vary widely. The 2026 contribution limits allow for significant savings—up to $24,500 for standard contributions, with an additional $8,000 catch-up for those over 50. If your target date fund’s fees are eating into those contributions, it’s worth exploring lower-cost alternatives in your plan, such as index funds.

The Bottom Line

The investors who performed best in February 2026 weren’t the ones making dramatic moves. According to Alight Solutions, there were zero above-normal trading days during a month of market volatility, and total transfers amounted to just 0.16% of starting balances.

But those same disciplined investors were quietly rebalancing—trimming exposure to areas where they felt overweight and rebalancing toward geographic diversification.

That’s the signal to watch. Not panic. Not market timing. Just the quiet, disciplined work of restoring intention to your portfolio.

As one retirement expert put it: “Risk should change by choice, not by accident”.

Take 15 minutes today to log into your 401(k) account. Look at your current allocation. Compare it to your target. And if you see drift, take action. Your future self will thank you.

Urgent Alert: If Your 401(k) Account Shows This Signal, It’s Time to Rebalance