10 Reasons to Rebalance Your All-Stock 401 (k) Before the Market Shifts

An all-stock 401(k) can produce strong gains when the market is rising, which is why many retirement savers stick with that approach for years. The problem is that the closer you get to retirement, the more a market downturn can affect your plans. Growth still matters, but so do factors like risk, income needs, and when you expect to start withdrawing money. That is why many investors rebalance their portfolios from time to time. Rebalancing means adjusting your investments to keep them aligned with your goals, timeline, and comfort with risk.

Your Risk May Have Drifted Without Permission

Portfolio allocations do not stay fixed. Someone who started with a balanced portfolio years ago may now have a higher share percentage of stock than bonds. Rebalancing brings the portfolio back to its target mix by trimming investments that have grown too large and adding to those that have fallen behind. That helps keep the portfolio aligned with the investor's original goals instead of letting market gains dictate the allocation.

A Market Decline Has Greater Consequences Near Retirement

A major market decline is easier to recover from when retirement is still decades away. The situation changes when retirement is only a few years off. A sharp drop can reduce account values just as withdrawals are about to begin. Selling stocks during a downturn also means locking in losses and leaving fewer shares to benefit from a recovery. Rebalancing can help reduce that risk by shifting some money into lower-volatility investments that may provide a source of income when stock prices are down.

Stocks Have Outpaced Other Asset Classes

The S&P 500 has produced substantial gains over the past decade, while bonds have delivered much lower returns. As a result, many retirement portfolios now contain a higher percentage of stocks than they did originally. Rebalancing captures part of those gains and redistributes assets according to a predetermined plan. The purpose is not to identify market peaks but to maintain the intended allocation.

Bonds Serve A Different Purpose Than Stocks

Bonds are not expected to match stock-market returns over long periods. Their primary role is portfolio stabilization and income generation. High-quality bonds have historically experienced smaller price swings than stocks and have often provided diversification benefits during periods of market stress. Retirement portfolios that consist solely of stocks depend entirely on equity market performance. Adding bonds introduces another asset class with different return characteristics. Rebalancing can restore that diversification if stock gains have pushed bonds out of the portfolio or reduced their allocation to a minimum.

Index Funds Can Still Create Concentration Risk

Broad-market index funds contain hundreds of companies, but market-cap weighting gives larger companies a greater influence on performance. When a small group of large firms accounts for a substantial share of market gains, investors may become more dependent on those companies than they realize. Rebalancing can reduce concentration by adding exposure to international stocks, small-cap stocks, value-oriented funds, bonds, or cash holdings. Diversification is not limited to the number of securities owned. It also depends on how portfolio assets are distributed across markets, sectors, and investment styles.

Your Retirement Timeline May Be Different Today

Retirement planning changes over time. A saver who expected to retire at age 67 may now plan to retire earlier or later. Income needs, household expenses, and financial obligations can also change. An allocation chosen years ago may no longer match current circumstances. Rebalancing creates an opportunity to compare the portfolio with present-day goals. Some investors may determine that a high stock allocation remains appropriate. Others may decide that additional bonds or cash reserves are warranted. The decision should reflect current retirement plans, not assumptions made years earlier.

Future Contributions Can Help Correct Imbalances

Selling investments is only one way to rebalance a portfolio. New contributions can also be directed toward asset classes that represent a smaller percentage of the account than intended. For example, if stocks have grown to 90% of a portfolio when the target is 75%, future contributions can be allocated to bonds or other underweighted assets. This method gradually restores the target allocation without requiring immediate sales. In tax-advantaged retirement accounts, investors can use either approach or combine the two strategies, depending on their circumstances.

Some Funds Rebalance Automatically

Many target-date funds and balanced funds automatically adjust allocations to maintain a predetermined mix of stocks, bonds, and cash. Investors who hold these funds may already have a built-in rebalancing process. However, additional investments outside those funds can alter the overall allocation. A target-date fund paired with several stock funds may result in a portfolio with more stock exposure than intended. Reviewing all holdings together provides a more accurate picture of the account's actual allocation and determines whether further adjustments are necessary.

Written Rules Improve Consistency

Many financial professionals recommend reviewing portfolio allocations regularly. Common review intervals include quarterly, semiannual, and annual. Another method involves setting allocation thresholds. For example, an investor may rebalance whenever an asset class moves five percentage points above or below its target. Written guidelines establish a consistent process for portfolio maintenance. Without predetermined rules, allocation decisions are more likely to be influenced by recent market performance or short-term events rather than long-term retirement objectives.

Rebalancing Connects The Portfolio To Retirement Goals

Rebalancing starts with a simple question: does your portfolio still match your retirement plans? Someone who expects to retire in five years may need a different mix of investments than someone with 30 years left to work. Factors such as retirement timing, income needs, and risk tolerance all play a role. Stocks can still make up most of a retirement account, especially for younger investors, but rebalancing helps ensure the allocation reflects those goals rather than years of market gains.