Risk Concentration: What It Is, Why It Matters, and How to Fix It
Risk concentration is one of the most underestimated threats to long-term financial security. It occurs when too much of your wealth is tied to a single asset, company, sector, currency, or country. A loss in that one area can cause damage that takes years to recover from. Most investors recognise the principle of “don’t put all your eggs in one basket,” yet concentration creeps into portfolios in ways that are easy to miss until it is too late.
Consider a South African employee who holds a large block of their employer’s shares through a staff scheme, owns a residential property in Johannesburg, and has most of their retirement savings in a local balanced fund with heavy exposure to South African equities and bonds. On paper, they own several different assets. In reality, all of them are closely tied to the performance of the South African economy and the rand. A serious economic shock or currency depreciation would hit each of these simultaneously. Investing offshore from South Africa is one structural way to break this kind of local concentration, but it is only one piece of the solution.
This guide explains exactly what risk concentration means, identifies the most common traps South African investors fall into, shows you how to measure it in your own portfolio, and outlines practical ways to reduce it, including tax-efficient strategies specific to the South African context.
What Risk Concentration Actually Means
Risk concentration describes the degree to which your portfolio’s returns, and your financial security, depend on the performance of a narrow set of factors rather than a broad spread of independent ones.
There are four main forms of concentration worth knowing:
- Single-asset concentration: A disproportionate amount of your wealth sits in one holding, such as a single company’s shares or one property.
- Sector concentration: Your investments are clustered in one industry, such as financial services, mining, or resources, which tend to move together.
- Geographic or country concentration: Most of your assets are exposed to one country’s economy, currency, and political risk.
- Currency concentration: Your wealth is overwhelmingly denominated in one currency, meaning a depreciation in that currency erodes your real purchasing power across the board.
Each form carries what professionals call idiosyncratic risk. This is simply the risk that is specific to one thing rather than spread across many things. Broad market risk affects almost all assets during a downturn, but idiosyncratic risk means you can suffer a serious loss even when markets overall are doing fine.
To make this tangible: imagine your total investable wealth is R2 million. If R800 000 of that sits in a single company’s shares, 40% of everything you own lives and dies with that one business. A corporate governance failure, a regulatory change, or a sector-specific downturn could halve that holding without touching the rest of the market at all.
The antidote to concentration is genuine currency diversification combined with spread across asset classes and geographies. Identifying where your concentration actually sits, however, requires a deliberate look at what you own.
Why Concentrated Portfolios Carry Greater Retirement Risk
The mathematics of loss are asymmetrical, and that asymmetry becomes far more consequential as you approach or enter retirement.
A simple example makes this clear. If a holding falls 50%, it needs to rise 100% just to return to where it started. A 30% fall requires a 43% recovery. The deeper the loss, the steeper the climb back. The more time that recovery demands. Time is the one resource that diminishes as you age.
This connects directly to sequence-of-returns risk, the danger that a large loss arrives at precisely the wrong moment in your financial life. If you are drawing down on a living annuity (a retirement income product where you stay invested and draw an income you choose within regulatory limits, while your remaining balance can be passed to your beneficiaries), a sharp drop in a concentrated portfolio early in retirement can permanently impair the capital you rely on. You are forced to sell units at depressed prices to fund income. Fewer units remain to participate in any eventual recovery.
Staying invested over time matters enormously, but only if you have the capital base left to stay invested with.
Regulation 28 (the rule that limits how much of a retirement fund can sit in each asset class, to keep retirement savings diversified) provides some structural protection against concentration inside pension funds and retirement annuities. But Regulation 28 only governs retirement fund assets. Property held in your personal name, employer shares, offshore accounts, and other personal investments sit entirely outside its scope. Many South Africans carry significant concentration in the very assets Regulation 28 cannot reach.
Getting the balance right is complex enough that working with financial advisors for retirement planning is often well worth the cost. The risk of getting it wrong in your sixties is simply too high.
Common Concentration Traps South African Investors Fall Into
I see the same concentration patterns again and again in the clients I work with. They are not obvious until you look, but once you do, they are impossible to ignore.
Trap 1: Overreliance on GEPF membership as a retirement plan
Members of the Government Employees Pension Fund (the retirement fund for South African public servants) sometimes treat their defined benefit entitlement as their entire retirement provision. The GEPF is a genuine asset, and the income it provides is valuable. But I have seen careers interrupted by medical retirement, retrenchment, or policy change. When that happens, there is nothing else to fall back on. Diversifying beyond the GEPF, even modestly, matters.
Trap 2: Concentrated employer share schemes
Many corporate employees accumulate company shares through staff incentive schemes over years of service. By the time they notice, a large fraction of their net worth tracks a single company’s share price. They also depend on that same company for their monthly income. If the company stumbles, both income and capital get hit at once. I have advised several clients through this scenario, and the earlier you address it, the better.
Trap 3: JSE sector dominance in local funds
The Johannesburg Stock Exchange is dominated by financials, resources, and industrials. A South African investor who holds multiple local unit trust funds may feel diversified but often holds overlapping exposure to the same handful of JSE-listed counters. True diversification requires looking through the fund to the underlying holdings.
Trap 4: Excessive property weighting
Property feels safe because it is tangible. A portfolio that is 60 or 70 percent residential and commercial property in one metro area is deeply concentrated, even if it does not feel that way. Property investment strategies in South Africa can play a legitimate role in a portfolio, but property should be sized as one allocation, not the whole answer.
Trap 5: Rand-denominated portfolio with global needs
Holding all your savings in rand-denominated assets creates currency concentration. If you plan to travel, have family abroad, or simply want purchasing power that keeps pace with global costs, a portfolio that earns and stores entirely in rands is exposed to rand depreciation. A partially offshore-diversified portfolio is not immune to rand weakness, but it gives you some natural protection.
How to Measure Concentration in Your Own Portfolio
Measuring concentration is simpler than most investors expect. The goal is to produce a clear picture of what percentage of your total wealth is exposed to each single factor. Nothing stays hidden once you do this properly.
Step 1: Calculate individual holding percentages
Add up the total market value of everything you own: shares, funds, property equity, pension values, offshore holdings, cash. Then divide each individual holding or account by that total. Any single position above 10% of your total wealth deserves scrutiny. Any position above 20% is a meaningful concentration by most widely used rules of thumb. These thresholds are not regulatory requirements; they are practical guidelines that many financial planners find useful as a starting point.
Step 2: Look through funds to underlying exposures
Unit trust funds and ETFs hold individual securities. Use the fund fact sheet to identify the top ten holdings and the sector weightings. If multiple funds in your portfolio share the same top holdings, your real diversification is lower than the number of funds suggests. This is the step most investors skip, and it is often the most revealing.
Step 3: Aggregate across all accounts
Many people mentally separate their retirement annuity, their living annuity, their personal share portfolio, and their property. Concentration exists at the total wealth level, not the account level. Combine everything into a single view before drawing any conclusions.
Step 4: Check currency exposure
Estimate what percentage of your total wealth is in rands versus hard currencies such as dollars, euros, or pounds. A portfolio that is 95% rand-denominated carries meaningful currency concentration for a globally mobile retiree.
Once you have this picture, you are ready to act. Getting professional retirement planning advice before making significant changes is sensible, especially where tax or pension rules are involved.
Practical Ways to Reduce Risk Concentration
Reducing concentration rarely requires selling everything at once. There are several targeted strategies, each with a distinct South African tax or regulatory angle. The strategy that makes sense depends on what concentration you are dealing with and how soon you need to address it.
Strategy 1: Use your annual CGT exclusion to trim concentrated positions gradually
Capital gains tax (CGT) is the tax on profits when you sell an asset for more than you paid. In South Africa, each individual has an annual CGT exclusion (currently R40 000, though tax rules change and you should verify the current threshold with SARS or a tax professional). You can sell a portion of a concentrated holding each tax year to stay within or close to this exclusion. This spreads the tax cost over several years rather than triggering a large liability in one go.
Strategy 2: Redirect new contributions away from concentrated assets
Rather than selling what you already hold, you can reduce concentration over time by directing all new savings into underrepresented asset classes and geographies. This costs nothing in tax and builds genuine balance incrementally. If you are saving R5 000 per month, where those contributions land matters far more over ten years than you might expect.
Strategy 3: Channel savings into a retirement annuity
A retirement annuity (a tax-advantaged product for saving towards retirement outside an employer fund) allows contributions of up to 27.5% of taxable income, subject to an annual rand cap (verify the current cap with your financial adviser, as it adjusts periodically). Contributions are deductible, investments inside the RA fall under Regulation 28’s diversification rules, and the forced diversification that Regulation 28 imposes can work in your favour if your personal portfolio is concentrated. You can read more about how retirement annuities are taxed in South Africa.
Strategy 4: Use a tax-free savings account for offshore or equity exposure
A tax-free savings account (TFSA) allows up to R36 000 per year in contributions (verify current limits with SARS), with all growth, dividends, and withdrawals completely free of tax. Choosing a globally diversified fund inside a TFSA is a clean, tax-free way to build a position that counterbalances rand-heavy concentration elsewhere.
Strategy 5: At retirement, consider splitting between a living and a life annuity
A life annuity (a retirement income product that pays a guaranteed income for life in exchange for your capital) eliminates the investment and longevity risk on that portion of your savings, while a living annuity keeps you invested and flexible. Splitting between the two at retirement is a practical concentration-reducer at the income level: you are not wholly dependent on one structure. What a life annuity is and how it works explains the mechanics in detail. Pairing this decision with a well-considered currency diversification strategy means you are addressing both the asset structure and the currency exposure simultaneously.
Concentration Risk Once You Are Already Retired
Retirement changes the nature of concentration risk in one critical way. You are no longer adding to your portfolio; you are drawing from it.
Your drawdown rate, the percentage of your retirement capital you withdraw as income each year, determines how long your money lasts. A high drawdown rate from a concentrated portfolio is doubly dangerous: if a large, concentrated position drops sharply, you are selling impaired assets to fund living expenses. The capital available for recovery is permanently smaller.
A tiered or bucket approach can help manage this. Think of your retirement portfolio in three layers: a cash or near-cash bucket to fund the next one to two years of income without touching invested assets, a medium-term bucket in defensive assets to replenish the cash layer, and a long-term growth bucket invested for the decade ahead. Concentration risk in the growth bucket matters far less when you are not forced to sell from it immediately to pay this month’s expenses.
For the guaranteed income layer, guaranteed annuity rates are worth reviewing periodically because they change with interest rates. Working with a financial adviser in retirement helps ensure your bucket sizes and drawdown rate stay aligned as your circumstances evolve. This is not something you set once and forget; it requires periodic review.
Frequently Asked Questions About Risk Concentration
What is the difference between risk concentration and diversification?
Risk concentration describes how much of your wealth depends on a narrow set of factors. Diversification is the practice of spreading exposure so that no single factor can cause catastrophic loss. They are opposite ends of the same spectrum. A well-diversified portfolio deliberately minimises concentration across assets, sectors, currencies, and geographies.
How much concentration is too much in a portfolio?
A widely used rule of thumb is that any single holding above 10% of your total wealth warrants scrutiny, and any position above 20% is a meaningful concentration risk. These are practical guidelines, not regulatory limits, and the right threshold depends on the nature of the holding, your age, and how close you are to drawing on the capital. Knowing when to invest in the stock market matters less than knowing how much of your total capital is at risk in any one place.
Does Regulation 28 protect against concentration risk?
Regulation 28 provides built-in diversification guardrails for assets held inside pension funds, provident funds, and retirement annuities. It limits exposure to equities, property, and single issuers, among other rules. However, Regulation 28 only covers retirement fund assets; personal share portfolios, property in your own name, employer share schemes, and offshore personal investments are entirely outside its reach.
Can I reduce concentration risk without a large tax bill?
Yes. You can redirect new contributions toward underweighted asset classes rather than selling existing holdings. You can also use the annual CGT exclusion to trim concentrated positions gradually across multiple tax years. Retirement annuity contributions and tax-free savings accounts both offer ways to build a diversified position in a tax-efficient structure. The key is to plan the process rather than react to a loss.
Is holding only South African assets a form of concentration risk?
It is, and for South African investors it is one of the more significant forms. A portfolio entirely in rands, invested in JSE-listed equities, local bonds, and South African property, is exposed to a single country’s economic performance, political environment, and currency. A rand depreciation reduces your global purchasing power even if nominal rand returns look acceptable. Offshore diversification is one of the most direct ways to address this.
The Bottom Line on Risk Concentration
Risk concentration is the condition where too much of your financial security depends on too few things moving in the right direction. It develops gradually, through employer share accumulation, property weighting, or simply leaving money in familiar local assets for years without review.
The danger is amplified at retirement, where a concentrated loss arrives at the moment you can least afford it and have the least time to recover. Measuring your concentration honestly, across all accounts and including currency, is the essential first step.
Three concrete actions to take now: calculate what percentage of your total wealth sits in your three largest individual exposures; check whether your local funds overlap in their underlying JSE holdings; and assess what proportion of your portfolio is in rands versus hard currencies. Then make a plan to address what you find, ideally with the help of finding the right financial adviser for retirement planning.
The principle behind diversification is not to avoid risk entirely, but to ensure that your financial future does not hinge on any single bet. Time in the market beats timing the market, but only if the portfolio you stay invested in is resilient enough to survive the inevitable volatility along the way.
This article provides general information and is not personal financial advice. Tax rules, contribution limits, and regulatory thresholds change regularly. Please consult a qualified financial adviser or tax professional before making decisions based on this content.