Rebalancing Your 401(k): Staying on Track

The Concept of Portfolio Drift

Portfolio drift occurs when the different investments in your 401(k) grow at different rates, causing your actual asset allocation to shift away from your original target. For example, if you start with a “moderate” mix of 60% stocks and 40% bonds, a strong year in the stock market might push your stock holdings up to 70%. While this looks like a gain, it means your portfolio is now more aggressive and riskier than you intended. Rebalancing is the disciplined process of bringing those percentages back in line with your chosen strategy.

Step 1: Identify Your Current Allocation

The first step in rebalancing is to log into your 401(k) portal and look at your current “Asset Mix” or “Pie Chart.” You need to compare the actual percentage of your money in each category—such as Large-Cap Stocks, International Stocks, and Bonds—against the target percentages you originally set. Most modern 401(k) platforms provide an “Analysis” or “Portfolio Review” tool that highlights exactly which funds are currently overweight (too large) or underweight (too small) compared to your goal.

Step 2: Choose Your Rebalancing Method

There are two primary ways to physically rebalance the funds in your account. The most common is the “One-Time Transfer,” where you sell a portion of your winning investments and use the proceeds to buy more of the lagging ones. Alternatively, you can use “Contribution Rebalancing,” where you leave your current balance alone but adjust your future payroll deductions to go 100% into the underweight funds until the account levels out. This second method is often preferred by those who want to avoid selling assets during high market volatility.

Step 3: Set a Rebalancing Frequency

Investors generally follow one of three schedules for rebalancing. The “Calendar Approach” involves checking the account on a set date every year, such as every January or on your birthday. The “Threshold Approach” involves rebalancing only when a specific asset class drifts by more than 5% from its target. Finally, many employer plans now offer “Automatic Rebalancing,” where you can toggle a setting that allows the plan’s software to periodically and automatically reset your portfolio to your target at the end of every quarter or year.

Tax-Free Advantage in a 401(k)

One of the greatest benefits of rebalancing inside a 401(k) is that it is a tax-neutral event. In a standard brokerage account, selling a winning stock to rebalance would trigger capital gains taxes. However, because 401(k) plans are tax-deferred, you can sell overperforming funds and buy underperforming ones as often as you like without owing any taxes on the growth. This allows you to maintain a disciplined “buy low, sell high” strategy without any immediate financial penalty from the IRS.

The Emotional Challenge of Rebalancing

Rebalancing is mathematically simple but emotionally difficult because it requires you to sell the investments that have been performing the best and buy the ones that have been performing the worst. During a bull market, it can feel counterintuitive to sell stocks; during a market crash, it can feel frightening to buy more of them. However, sticking to a rebalancing schedule removes emotion from the process, ensuring that you are consistently locking in gains and positioning yourself to benefit when out-of-favor assets eventually recover.

Primary Information Source

Financial Industry Regulatory Authority (FINRA): Rebalancing Your Portfolio