Sharpe Ratio: What is it?
At a glance:
• The Sharpe Ratio is a financial metric used to measure the risk-adjusted performance of an investment.
• This indicator helps you to understand whether the return on an asset or portfolio is sufficient to justify the volatility experienced by the investor over time.
• This ratio is an essential tool for rigorously comparing investments and making decisions aligned with your profile by adjusting the return achieved to the level of market fluctuation.
• At Carregosa NextGen, you will find all the specialist support and platforms you need to assess this relationship more effectively.
Two investments may yield the same 10% return after a year, but they may have followed completely different trajectories. Investment A rose steadily and gradually, while Investment B experienced sharp falls and steep rises, leaving investors exposed to severe market stress. Ultimately, the outcome was the same, but the level of risk was completely different.
This is why the Sharpe Ratio is so important. This indicator helps you to understand whether the returns you are achieving justify the risks you are taking. Find out what the Sharpe Ratio is, how it is calculated, and how you can use it to make better-informed investment decisions.
What is the Sharpe Ratio?
The Sharpe Ratio is a financial indicator used to measure the risk-adjusted return on an investment. It was developed by William F. Sharpe, an American economist and Nobel Prize winner, to help investors make more accurate comparisons of performance.
The ratio provides a straightforward answer to a basic question: what is the additional return for every unit of risk taken?
This ‘additional return’ is calculated based on the interest rate of a risk-free asset (for example, shorter-term government bonds). Meanwhile, risk is measured by volatility, or the degree to which returns vary over time.
In general, the higher the value, the better the historical risk-return ratio. A negative value indicates that the investment has underperformed compared to the risk-free asset. Conversely, higher values indicate greater efficiency in generating returns relative to the risk taken.
How is the Sharpe Ratio calculated?
The formula for calculating the Sharpe Ratio combines three simple variables:
Sharpe Ratio = (return on investment – risk-free rate) / standard deviation of return
Where:
• Return on investment: the total return generated by an asset.
• Risk-free Rate (Risk-Free Rate): the return you would obtain without taking any risks (usually indexed to short-term, 3-month treasury bills, such as US or European ones).
• Volatility: the intensity and frequency with which an asset's price fluctuates, measured statistically by standard deviation. The higher the volatility, the more unpredictable the price movement tends to be.
The result of this equation indicates the risk premium. If the Sharpe Ratio is 1, you will receive an additional 1% return for every 1% of risk you take on.
Practical example: Compare to decide
Imagine you are considering two global equity funds on your trading platform in a scenario where the current risk-free rate is 2%:
• Technology Fund (Fund A): annual return of 14% with a volatility of 12%.
• Stable Consumer Fund (Fund B): annual return of 10% with a volatility of 5%.
At first glance, Fund A seems more attractive due to its higher return of 14% compared to 10%. However, let’s apply the Sharpe Ratio:
• Sharpe Ratio for Fund A: (14% - 2%) / 12% = 1.00
• Sharpe Ratio for Fund B: (10% - 2%) / 5% = 1.60
Conclusion: Fund B demonstrates greater historical efficiency in optimising the risk-return ratio over the period and under the analysed assumptions. For every unit of risk taken on, Fund B offers a risk premium of 1.6%, whereas Fund A offers only 1%. Fund B provides a much smoother path to generating returns.
How should you interpret the result?
When analysing the Sharpe Ratio of an investment fund, ETF or portfolio on the GoBulling platform, the following market benchmarks can be used as a guide:
| Sharpe Ratio value | Possible interpretation | Cautionary note |
|---|---|---|
| Less than 0 | The return was below the risk-free rate. | This may suggest that the risk taken was not adequately rewarded |
| Between 0 and 1 | Limited risk/return ratio | Should be compared with similar assets |
| Between 1 and 2 | Potentially balanced risk/return ratio | Does not guarantee future stability |
| Between 2 and 3 | High historical performance | May not be sustainable in all periods |
| More than 3 | Exceptional performance over the period analysed | Requires validation of methodology, liquidity, and consistency |
The key difference between an investor who acts on impulse and one who acts with consistency is their understanding of risk.
Advantages and limitations: what you need to consider
To use the Sharpe Ratio effectively in your day-to-day investing, you need to strike a strategic balance between what it reveals and what it cannot predict.
Advantages (what you gain):
• Fair comparison: It enables you to compare two assets with completely different returns and volatilities, showing which one offers the best risk-to-return ratio.
• Focus on efficiency: It helps you look beyond ‘gross returns’. It enables you to determine whether a portfolio is performing well due to effective management or excessive risk exposure.
• Support with allocation: It is an excellent tiebreaker when you need to choose which funds or ETFs to add to your GoBulling portfolio.
Limitations (what you should monitor):
• Reliance on the past: The index is calculated based on historical data. Last year’s excellent risk-adjusted performance does not guarantee that volatility won’t spike in the future.
• Illiquid assets (watch out for property and private equity): This indicator may not be reliable for assets without a daily market price. In such cases, ‘return smoothing’ occurs, which makes volatility appear artificially low and the Sharpe Ratio deceptively high.
• It does not detect tail risk: The index assumes that markets follow a normal statistical distribution. Therefore, it cannot predict or measure the impact of extreme and rare events, such as "black swans” or systemic crashes.
Are you just starting out in the world of investing?
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Alternatives to the Sharpe Ratio
To achieve a more comprehensive analysis, it is best to combine several indicators. Read on to find out about some of the most relevant ones.
Sortino Ratio
The Sortino Ratio is an improvement on the Sharpe Ratio. The main difference is that it only considers downside risk (downside deviation).
This means that it only penalises returns that are below a certain target or minimum acceptable rate. It may therefore be a more appropriate metric for investors who are primarily concerned with losses.
It is particularly useful for strategies involving asymmetric returns or significant upside potential.
Alpha
Alpha is a measure of the additional return on an investment compared to its benchmark, considering the level of risk involved.
A positive alpha indicates that a fund has outperformed the expected return based on its market exposure.
While the Sharpe Ratio measures overall efficiency, alpha measures the ability to generate returns that exceed the market average.
Beta
The beta coefficient measures an asset’s sensitivity to the market.
• Beta greater than 1: higher volatility than the market;
• Beta less than 1: lower volatility;
• Negative beta: behaviour inversely related to the market.
Although beta does not measure efficiency, it helps you to understand the type of systematic risk that you are taking on.
Maximum drawdown
The maximum drawdown is the largest cumulative loss between a peak and the subsequent low point.
This indicator is particularly useful for evaluating risk during times of crisis. While an investment may have a good Sharpe Ratio, it could still experience sharp declines at certain times.
Sharpe vs. Other indicators: comparative table
| Indicator | What it measures | When it is useful | Limitations |
|---|---|---|---|
| Sharpe Ratio | Excess return per unit of volatility | Comparing portfolios, funds, or ETFs | Penalises both positive and negative volatility |
| Sortino Ratio | Return adjusted only for downside risk | Evaluate strategies with a focus on losses | Requires definition of minimum acceptable return |
| Alpha | Return above the benchmark | Assess value added by management | Depends on the choice of benchmark |
| Beta | Sensitivity to the market | Measure systematic risk | Does not measure return efficiency |
| Maximum drawdown | Largest fall between peak and trough | Assess losses during critical periods | Does not show the frequency of losses |
Sharpe Ratio: invest in the future with Carregosa NextGen
Understanding the Sharpe Ratio is an important step towards moving beyond simply looking at "how much it yields” and starting to analyse "how it yields”. It is vital to align returns with risk if you want to build a more robust strategy that suits your profile.
Invest with context, method, and support
Founded in 1833, Banco Carregosa is a leading independent leader in Wealth Management in Portugal. Carregosa NextGen builds on this experience, offering a new generation of investors the opportunity to start saving and investing using digital tools, alongside financial literacy, and specialist support.
In 2026, Banco Carregosa was named "Best Pure-Play / Boutique Private Bank” in Portugal by Euromoney for the second consecutive year, reinforcing its position in Private Banking and wealth management. This award is entirely at the discretion of the awarding body.
If you want to invest more wisely and avoid making impulsive decisions, contact us and start building your future.
GoBulling Trading Platform
With the support of the Banco Carregosa team and the analysis tools on the GoBulling platforms, you can check the volatility and efficiency indicators of the funds and assets you are tracking. This allows you to make decisions based on rigorous data rather than impulse. You can try our Demo Version* here.
* The DEMO account is intended solely for familiarising yourself with the platform. Please note that it may not fully replicate actual trading conditions.
Sharpe Ratio: FAQs
You can find the answers to the most frequently asked questions about the Sharpe Ratio below.
Does the Sharpe Ratio predict future returns?
No. The Sharpe Ratio is usually calculated based on historical data. While it can help to assess the relationship between risk and return in the past, it does not guarantee that this relationship will continue in the future.
What is the difference between the Sharpe Ratio and the Sortino Ratio?
While the Sharpe Ratio penalises all volatility, the Sortino Ratio focuses solely on downside volatility (downside deviation). This makes it a useful alternative for investors who are comfortable with price fluctuations provided they are upwards.
Is the Sharpe Ratio best for shares, ETFs or funds?
Although it can be used for shares, ETFs, funds or portfolios, it is most useful when comparing similar investments with the same currency, time period and calculation methodology.
Can I use the Sharpe Ratio to choose an ETF?
Yes, this can be one of the indicators to consider, particularly when comparing similar ETFs. However, it should be analysed alongside other factors, such as costs, liquidity, composition, currency, fund size, distribution policy, and currency risk.
Can I compare the Sharpe Ratio of an equity fund with that of a bond fund?
You can do so, but with caution. The Sharpe Ratio is most effective for comparing assets within the same asset class. It can be misleading to compare a growth stocks fund with a treasury bond fund solely on the basis of the Sharpe Ratio, as the nature and frequency of the risk are different.
What is the main limitation of the Sharpe Ratio?
The main limitation is that it treats all volatility as risk, including positive fluctuations. It also relies on historical data, which makes it less reliable for illiquid assets or strategies with asymmetric returns.
Is the Sharpe Ratio useful for illiquid investments (property or private equity)?
It is less reliable. Illiquid assets suffer from "return smoothing" because they are not quoted daily. This artificially lowers the calculated volatility, resulting in a misleadingly high Sharpe ratio. In such cases, metrics such as the Kaplan-Scholar index are more appropriate.
Does a high Sharpe Ratio mean I should invest?
Not necessarily. While a high Sharpe ratio may indicate good historical performance, it does not replace an analysis of the product itself, its risks, costs, time horizon, and suitability for the investor’s profile.
Disclaimer: This article has been prepared by Banco Carregosa for informational and educational purposes only. It does not constitute an investment proposal or recommendation to buy, nor does it constitute personalised financial advice. Investing in financial instruments carries risks, including the possibility of losing your initial investment. Past performance does not guarantee future results. Before making any investment decisions, we recommend that you consult an account manager or financial adviser to ensure that they are suitable for your risk profile and financial objectives.