© mayu85 / Shutterstock.com
You wake up this morning, and your 401(k) balance is down, and then you check it again with the same result. Do you need to do it a third time? There is a lesson here, as every time you check your balance, you are making a decision about whether to stay the course or get out, and the data on how that decision typically turns out is unflattering.
The SPDR S&P 500 ETF Trust (NYSEARCA:SPY) is down 3.5% year-to-date and over 5% over the past month, while the CBOE Volatility Index sits at 27.0, in the 93rd percentile of readings over the past year. Consumer sentiment has been stuck in pessimistic territory, with the University of Michigan Consumer Index registering 56.4 in January 2026, well below the 80-point threshold that signals neutral confidence. Every signal right now is pushing you to open that app and look. It’s this impulse that is the source of the problem.
The Cost of Watching the Number Move
DALBAR’s annual Quantitative Analysis of Investor Behavior has tracked the gap between market returns and what average investors actually capture for decades. In 2024, the average equity investor earned 16.54%, while the S&P 500 returned 25.02%, a gap of 848 basis points that DALBAR called the second-largest investor performance gap of the past decade. Over a 20-year horizon ending December 31, 2024, the average equity investor returned 9.24% annualized versus 10.35% for the S&P 50. That gap, compounded over two decades, is the difference between a $1 million portfolio and something meaningfully larger.
The mechanism behind that gap has a name: myopic loss aversion. Behavioral economists Shlomo Benartzi and Richard Thaler identified it as the combination of two forces. Investors feel losses more acutely than equivalent gains, and the more frequently they check their portfolios, the more often they encounter those losses and the more likely they are to act on them. Checking a portfolio daily yields a 46% chance of a decline. Checking annually drops that probability to roughly 25%. Checking every five years further reduces it to around 10%.
For someone with $1 million or more in a 401(k), a single poorly timed shift to bonds or cash can permanently impair the portfolio. The S&P 500 is up roughly 226% over the past decade. The investors who captured most of that return checked quarterly, confirmed their allocation was intact, and closed the tab.
What a Quarterly Review Actually Looks Like
A quarterly cadence is the right frequency, but only if you are reviewing the right things. The balance itself is not one of them. Here is what warrants attention:
Allocation drift: A portfolio that started at 70% equities and 30% bonds may have shifted after a volatile quarter, so rebalancing back to your target is a mechanical decision, not an emotional one. It forces you to buy what fell and trim what rose, which is the opposite of what panic-checking encourages.
Expense ratios: A 1% annual fee on a $1.5 million portfolio costs $15,000 per year in drag, so if your plan’s default options carry fees above 0.5%, check whether lower-cost index alternatives are available in the same plan.
Beneficiary designations: These override your will, which means that a life event, divorce, or death in the family that goes unaddressed can redirect a seven-figure account to the wrong person. In other words, it’s critical that you verify this at least once per year.
One Lever Worth Pulling Right Now
If you are between 60 and 63, there is a concrete action you can take that has nothing to do with watching the balance. Under SECURE 2.0, you qualify for the super catch-up contribution: In 2026, the standard catch-up limit for investors over 50 is $8,000, but those aged 60 to 63 can contribute up to $11,250 in catch-up contributions on top of the standard deferral limit. Every dollar contributed during a pullback buys more shares than the same dollar contributed at a peak.
The 10-year return on the S&P 500 of 226% did not happen in a straight line. It ran through corrections, scares, and periods where checking the balance felt unbearable. The investors who checked less frequently made better decisions, not because they were smarter, but because they gave their plan room to work.
Three actions that matter more than checking your balance today:
Set a calendar reminder for one quarterly review date and close the app until then. Use that session to rebalance if the drift exceeds 5 percentage points from your target allocation.
If your combined household income in 2024, which is what is used in 2026, exceeded $109,000, model whether a partial Roth conversion in a lower-income year could reduce your future required minimum distributions and the Medicare premium surcharges they can trigger. Note that one single dollar over can trigger the extra $81.20 monthly charge. A fee-only advisor can run this calculation in an hour.
If you are 60 to 63, confirm with your plan administrator that the super catch-up limit is available and increase your deferral before year-end.