Portfolio Builder
This tool builds a portfolio from chosen funds and their weights, then works out the characteristics of the whole, the ones you cannot read fund by fund: weighted average ongoing charges, actual exposure by region and sector once overlaps are added up, the number of distinct holdings after consolidation, and the share taken by the largest underlying position. That last figure is the one that surprises most often: a portfolio of five different funds can concentrate more than ten per cent in a single company, because the same firm sits at the top of a world fund, a technology fund and a thematic fund. Overlap is the most common flaw in a portfolio built fund by fund, and it only shows at this level of aggregation.
Published by Radif Partners · Updated
Frequently asked questions
What does this portfolio tool do?
It takes the funds you select, applies the weights you choose, and shows what the combination holds: the geographic and sector overlap between funds, the weighted average of their ongoing charges, and how the mix would have behaved over the horizons the issuers publish. It compares combinations; it does not recommend one.
How many ETFs does a portfolio need?
Fewer than most people assume. A single broad world fund already holds well over a thousand companies across developed markets, and adding a second fund on a similar index mostly duplicates it: the overlap view shows how much. Two to four funds is enough for most long-term portfolios, and each extra line adds a decision to maintain rather than diversification.
Does the tool account for tax?
No. Tax depends on your country, on the wrapper you invest through and on whether the fund accumulates or distributes, none of which the tool knows. A distributing fund in a taxable account can cost several tenths of a per cent a year in friction that never appears in a performance figure, which is why the accumulating or distributing column matters as much as the charge.
What overlap measures
Two funds can share a large part of their holdings without their names hinting at it. A world index already contains about a quarter technology and a majority of American equities: adding an S&P 500 fund or a technology fund to it concentrates the portfolio instead of diversifying it. The tool adds up each fund's weighted holdings and returns consolidated exposure, which shows whether the line you are adding brings anything the portfolio did not already have.
What the tool does not do
It recommends no allocation and sets no risk profile: that would be investment advice, which belongs to an authorised professional and to your personal circumstances. It takes no account of your future contributions, your horizon, your other assets or your tax position. Finally the underlying holdings are those published at the last data update: an index rebalances, and a composition changes between two publications.
What to check before adding a line
Three numbers decide whether an extra position contributes anything. The share of the largest underlying company: if it rises, the new line concentrates the portfolio. Weighted costs: an expensive fund with a small weight changes little, with a large weight it sets the cost of the whole. And the number of distinct holdings after consolidation: if it stays flat while the portfolio grows, the new line is a repetition.