Only one of the top 50 performing funds over the period 1997 to 2002 remained in this group for the following five-year period to 2007, according to an analysis of industry data by Heartwood Wealth Management. The average ranking for the funds fell to 1,140. Only 16 of the top 50 funds from 1997 to 2002 made it into the top 500 for the period 2002 to 2007, and 23 fell out of the top 900. A further 13 of the funds are no longer ranked in the top 2,000. This explains, said Heartwood, why 15 out of the 50 funds now have third or fourth quartile rankings. David Lough, Heartwood's chief executive, said: “Our analysis shows the importance of regularly reviewing your investment portfolio because strongly performing funds may not persist. Those investors who follow the latest investment trends, which are often focused on asset classes that have higher than average levels of risk, are the most likely to suffer from this. "Investors should place a greater focus on selecting funds that are likely to remain suitable longer term or be prepared to get help in maintaining a portfolio that makes sense as markets change.” Heartwood's research was based on an analysis of Lipper data as of 16 October 2007. Heartwood provides investment, tax and retirement planning advice for ultra and high net worth individuals from its offices in London and Tunbridge Wells. Founded in 1988 as a division of southeast-based solictors Cripps Harries Hall, it became independent in December 2005. Heartwood now manages and administers over £1 billion ($2 billion) of funds for clients.