Tracker funds buy into yesterday's success stories The headline-grabbing element was that 10 million randomly picked portfolios, based on how a monkey would apparently select shares, performed better over four decades, once the risk taken was considered, than an index based on the size of the companies included on it, which is how tracker funds select shares. Essentially, you buy into yesterday's success stories. Instead, it is suggested that indices be based on other measures, such as dividends, sales or "book value," which is the money a company might realise if it was wound up and its assets sold. Fortunately for investors, such beasts already exist - with a twist. The world of exchange-traded funds (ETFs), which are shares listed on the stock exchange but that behave more like funds, has forged ahead in the development of esoteric investments. Some track stock markets in a different way. The SPDR S&P UK Dividend Aristocrats ETF, for example, aims to track the performance of the 30 highest-yielding UK shares of companies that increased or kept steady dividends for at least 10 consecutive years. It's top holdings include defence giant BAE Systems, insurer Amlin and energy firm SSE. It pays an income of 3.4pc and carries a charge of just 0.3pc a year. There are plenty more examples, although you may need professional guidance when picking ETFs. And of course academic conclusions are not always watertight.