SIGnet Investors’ Index®
What is the SIGnet Investors’ Index?
Many SIGnet members like to monitor the performance of their investment portfolios against a benchmark. By doing so you can determine whether your investment strategy is producing satisfactory results or whether you should reconsider and seek to improve it.
Having decided to benchmark your performance the next question is what to benchmark against? UK investors typically choose the FTSE100 or FTSE-All Share indices as benchmarks, but these indices suffer from a fatal flaw. They are market capitalisation weighted, which means that the index is heavily influenced by the performance of the largest companies (by market capitalisation). Typical UK investor portfolios are not weighted solely to the largest companies so these standard indices do not provide a very good benchmark for such portfolios.
SIGnet members (in particular, Andrew Hall) therefore devised an alternative index, designed to be more representative – the SIGnet Investors’ index (SII). This index is simply an equally weighted index of ALL UK listed and quoted companies’ share prices. It could be argued that this index offers a more representative benchmark for UK investors to measure their performance against.
The SII is recalculated weekly, by aggregating the percentage share price moves of all its constituents. That means that, in effect it is reweighted weekly. The universe of stocks used includes investment trusts so there may be an element of double counting of some stocks that also happen to be significant constituents of one or more investment trusts. We decided to include investment trusts, as these are often constituents of members’ portfolios.
Note that the SII is NOT a total return index so if you use it to benchmark your own portfolio against you need to deduct gains from dividends you have received for a fair comparison. After some analysis, we concluded that dividends did not play a big role in performance differences between the SII and conventional indexes such as the FTSE100 or FTSE All-share. That analysis also showed that performance was not overly distorted by the inclusion of “penny stocks” (which are more susceptible to large price swings), as these form only 16% of SII constituents.
In Memory of Andrew Hall
The SIGnet Investors’ Index was most recently produced by Andrew Hall, who sadly passed away. We are grateful for his contributions and dedication. ShareScope has now taken on the responsibility of producing the figures for us and you can view the figure if you are a ShareScope subscriber: Log in to ShareScope, go to Other Lists/Indices/All Indices and enter “SIG” in the ‘Find a Share’ field. You can also use ‘add SIG to a portfolio’ and use the ShareScope Settings function to see other data on the Index (e.g. annualised returns, moving averages, slope of Trend lines), and you can use the Chart function – just as you would for a share.
