How Does a Portfolio Become Too Concentrated?

A portfolio becomes too concentrated when too much of your wealth depends on one stock, company, sector, asset class, or investment theme. This can happen through employer stock, successful investments, overlapping funds, or market growth. The risk is that a decline in one area could significantly affect your retirement portfolio.

You may own several stocks and mutual funds across a 401(k) and other investment accounts, leading you to assume your portfolio is diversified.

But are you?

If you’re approaching retirement with $500,000 or more invested, concentration deserves a closer look. Once you switch from earning a paycheck to drawing income from your portfolio, recovering from a major loss in one asset becomes a large challenge.

At SGL Financial, our financial professionals in Chicagoland can help evaluate your entire portfolio, including overlapping holdings, concentrated risks, taxes, and retirement income needs. 

What Is a Concentrated Portfolio?

A concentrated portfolio has too much of its value exposed to one investment, company, sector, asset class, or other source of risk. There is no universal percentage that makes a portfolio “too concentrated.” 

For instance, a 10% position may be reasonable for one investor and excessive for another.

The key question is: How much of your financial future depends on this investment, and what would happen if its value declined substantially?

How Can Employer Stock Create Concentration Risk?

Employer stock can create significant concentration risk, particularly when a large portion of your financial life is tied to the same company. This can happen through:

• Restricted stock units (RSUs)
• Incentive stock options (ISOs)
• Employee stock purchase plans (ESPPs)
• Stock bonuses or grants
• Employer stock held in a retirement plan

For example, if you have a $1.5 million portfolio and $500,000 is invested in your employer’s stock, one-third of your portfolio depends on the performance of one company.

Your actual exposure may be even greater because your salary, bonus, benefits, and career prospects may also depend on that employer. If the company struggles, several parts of your financial life could be affected at the same time.

Selling employer stock may create tax consequences, so any decision should be evaluated alongside your broader retirement and tax strategies.

Can a Successful Investment Become Too Large?

Yes. Investment success is one of the most common ways concentration develops.

Suppose you invested $50,000 in a stock that grew to $400,000. You may hesitate to sell because the investment has performed well or because selling could result in a large capital gain.

But consider this question:

“If I had $400,000 in cash today, would I invest all of it in this one company?”

Your answer can help you evaluate the position based on its current size rather than its original cost.

Can Market Growth Make a Portfolio More Concentrated?

Yes. Your portfolio can become more concentrated without buying additional investments.

For instance, if one sector or asset class outperforms the rest of your portfolio, its weight may gradually increase. This can also happen within broad market indexes as the largest companies grow and come to represent a larger share of the index.

As a result, your current allocation may differ significantly from the allocation you originally selected.

Be sure to listen to our podcast episode: “Game, Set, Money.”

Does Owning More Funds Mean You’re Diversified?

No. Owning more funds does not automatically create diversification. Several mutual funds or ETFs may hold many of the same companies. For example:

You may own four funds, but still have substantial exposure to the same stocks. 

True diversification depends on the underlying holdings, not the number of funds or account statements you have.

Can Different Accounts Hide Portfolio Concentration?

Yes. Reviewing accounts separately can make it difficult to see your overall exposure.

You may have various types of investment and savings accounts, such as:

• A current 401(k)
• An old 401(k)
• Traditional and Roth IRAs
• A taxable brokerage account
• Employer stock
• Your spouse’s accounts

Each account may appear diversified on its own. But when combined, the same companies, sectors, or asset classes may represent a large portion of your overall wealth.

At SGL Financial, our Chicagoland professional financial team helps you evaluate investments in the context of your broader financial picture, rather than treating each account as an isolated decision. By analyzing all of your total holdings as a single, unified portfolio, we ensure your overall risk, asset allocation, and retirement income strategy stay fully aligned with your long-term goals.

Why Does Concentration Matter More Near Retirement?

Concentration can become especially important near retirement because you may have less time and fewer contributions available to recover from a major loss.

During your working years, future earnings and contributions may help offset market declines. In retirement, you may be withdrawing money from your portfolio to supplement Social Security, pensions, or other sources of income.

A concentrated investment that falls sharply while you are taking withdrawals could place additional pressure on your retirement income strategy.

At SGL Financial, we consider the relationship between portfolio allocation and retirement income needs as one part of our 4-pillar planning process. We tailor your portfolio allocation directly to your specific retirement income needs, because effective planning isn’t about collecting as many investments as possible. It’s about giving you total clarity over the risks you’re taking and ensuring every dollar actively supports your vision for the future.

Read our Quick Guide: “What Retirement Planning Details Do People Often Overlook?”

Should You Sell a Concentrated Investment?

Deciding what to do with a concentrated investment requires weighing your options and the potential tradeoffs of each.

Selling may create taxes, while holding the position may leave you exposed to unnecessary risk. Depending on your circumstances, possible strategies may include:

• Gradual sales
• Tax-aware rebalancing
• Selling across multiple tax years
• Donating appreciated securities
• Directing new investments toward underrepresented areas

Before making a significant change, consider working with fiduciary financial professionals in the Chicago metro area who evaluate the impact on your portfolio, taxes, and retirement income.

Read our blog: When Should You Update Your Retirement Plan?

Is It Time to Look Under the Hood of Your Portfolio?

If you’re approaching retirement and have investments, it’s worth knowing how much of your financial future depends on any one company, sector, or investment. 

Not sure? Let the SGL Financial team help you look beyond isolated account balances to get a clear, complete picture of your true risk. Schedule your complimentary Portfolio Analysis today, and let us help you build a cohesive, diversified strategy designed for lasting income and peace of mind.

Frequently Asked Questions About Portfolio Concentration

What Percentage of One Stock Is Too Much?

There is no universal percentage. The answer depends on your total assets, taxes, retirement income needs, risk tolerance, and other investments.

Can You Be Too Concentrated in the S&P 500?

Yes. Although the S&P 500 includes hundreds of companies, its largest holdings and sectors can represent a significant portion of the index.

Are ETFs Enough to Diversify a Portfolio?

No. Multiple ETFs may own many of the same underlying securities. Review fund holdings rather than relying on fund names.

Can Different Investment Accounts Create Concentration Risk?

Yes. A portfolio may appear diversified when each account is reviewed separately, but the same companies, sectors, or asset classes may appear across multiple accounts. Reviewing your investments as a whole can provide a clearer picture of your overall exposure.

Should You Diversify Employer Stock Before Retirement?

Yes. Employer stock concentration is worth evaluating before retirement. Whether to sell depends on taxes, cost basis, other assets, and your retirement income needs.

How Often Should You Review Portfolio Concentration?

You should review your portfolio at least twice a year. It may also be beneficial to review it sooner following major market movements, equity compensation events, retirement, an inheritance, or other significant changes to your financial situation.

Can Portfolio Concentration Affect Retirement Income?

Yes. A major decline in a concentrated position during retirement withdrawals could reduce the assets available to fund future expenses.

Can Selling a Concentrated Investment Create Tax Consequences?

Yes. Selling an appreciated investment may result in capital gains taxes. Tax considerations should be weighed alongside your overall investment strategy and retirement income needs before making a significant change.