If the market fell tomorrow the way it did in 2022, would you know how much your portfolio could lose? Many people know what they have earned, but not how far their portfolio has dropped along the way. In this tutorial I show you how to measure it on CloudPortfolios in a couple of minutes, how to read the full report and how to test changes with the "what if…?" simulator to understand their effect. I designed the site and its tools myself, and I'd rather you knew that from the start.
Step 1: build the portfolio
Go to Investing → Build portfolio. On the left is the database: more than 2,000 assets, including stocks, ETFs, bond ETFs, index funds and commodities. You can search by name or ISIN and filter by region, sector or currency. Each asset is added with the + button.
For this example I use a sample portfolio of five ETFs: US stocks (40%), stocks from other developed markets (20%), bonds (25%), gold (10%) and real estate (5%). You move the weights with the sliders or type them in, and they must add up to 100%. If you're not sure where to start, the Equal weight and Inverse volatility buttons give you a first split. And if your portfolio already sits with a broker, you can import it from a file.
Step 2: look at the worst fall before the return
On the right, the profile updates live with every change. There are many numbers, but I would start with one: the maximum drawdown, the largest fall from a peak to the next low. In this portfolio it was −23.8%, between December 2021 and September 2022. That's the first clue to the opening question: with this mix, in the worst stretch since 2010 the portfolio lost almost a quarter of its value. It's a past fall in this sample, not the maximum possible: a future fall could be larger.
Next to it you have the annual return, the volatility (how much the portfolio moves up and down), the Sharpe ratio (how much you earn for each unit of risk) and the diversification ratio, with its "Effective N", which tells you how many truly "independent" assets you hold. In the sample, the Effective N is 3.6: five assets behave like about 3.6, because part of what you own moves together.
Step 3: the full report
The Full report button opens the portfolio in detail: its growth against a world index, the return of each month, the split by sector, region and asset type, the drawdown chart, the risk in the worst months and the correlation between the assets.
Look at the In-sample and Out-of-sample tabs. The site splits history into two periods so you can see whether the portfolio behaved the same in the stretch you know and in the one that came after. It's the same idea the investment engine uses, which I'll cover in another tutorial.
Step 4: try "what if…?" before changing anything
This is my favourite part. Click Set as original and then change whatever you like. In the example I cut US stocks from 40% to 30% and raised gold from 10% to 20%. Every figure shows the difference from the original: volatility fell by 0.59 points and return by 0.36. The worst fall went from −23.8% to −22.2%.
Is that better or worse? It depends on what you are after. The tool doesn't decide for you: it shows what you gain and what you give up with each change, over the same months, so the decision is yours and based on data.
Before you draw conclusions
Everything you see is a hypothetical result based on past prices: price only, no dividends, no costs or taxes, and only assets that still trade today. The data are monthly closes in US dollars from January 2010 to September 2026, from an external provider (EODHD), and the site measures falls without reinvestment, as a percentage of the initial capital. It helps you understand the risk of a portfolio, not predict the future.
For now the tool is free and you don't need to sign up. Build your portfolio and look at its worst fall. In the next tutorial we'll do the same with a single company, and you'll see how even one of the largest in the world lost more than 40%.
Educational and informational content only, published on 6 November 2026. It is not financial, tax or legal advice, nor a personalised investment recommendation, nor an offer or invitation to buy any product. The assets in the example are used only to show how the tool works. Results are hypothetical and based on past prices (price only, no dividends, costs or taxes). Past performance does not guarantee future results, and all investing involves risk, including the loss of capital. Figures may have changed since publication. Before making a decision, consult an authorised professional.