According to a new report published by UK-based investment platform firm, FundExpert.co.uk, £269 billion ($435 billion) of private investor money is languishing in under-performing funds.

The research, which is based on analysis of 120 separate periods for every fund with at least a ten year track record, reveals that over 91 per cent of funds are “mediocre at best”, Fundexpert.co.uk said in a statement.

Only 70 funds out of a total universe of more than 750 consistently prove they can deliver over the longer-term, the firm said.

“While it would appear the vast majority of fund managers aspire to mediocrity our latest analysis shows that many don’t even manage to achieve that. For many thousands of private investors that buy and hold funds for long periods of time, this means a totally unacceptable level of under-performance they shouldn’t be prepared to put up with,” said Brian Dennehy, founder and managing director of FundExpert.co.uk.

FundExpert.co.uk, which has introduced a new fund rating service on the back of its findings, is urging private investors who typically buy and hold funds for long periods of time to review their holdings and move their money into one of the 70 funds it has awarded “vintage” status.

FundExpert.co.uk conducted detailed analysis to show how “vintage” ratings boost returns, taking into consideration the most popular investment sector, UK All Companies: £31 billion is in “ugly” funds - those which consistently under-perform their peers. Over ten years these “ugly” funds returned 102 per cent. However, in stark contrast “vintage” funds grew twice as much, by 209 per cent.

Even what Fundexpert.co.uk brands as the "mediocre" funds returned 71 per cent less over ten years, the firm said.