The FTSE 100 dipped below the 5,000 mark this morning after a short-lived rally at the start of trading.
Heavy losses in the battered US markets have spread to the UK and sent the index of 100 leading shares down more than 3%.
The FTSE 100 is in the black in early trading after falling 1% on opening, after S&P's downgrade of US debt sparked a further share sell-off across the globe.
Paul Spencer passed his five-year anniversary on the Rensburg UK Mid Cap Growth fund earlier this year after rejoining the group in 2006 boasting top-decile returns over all time periods.
Sharp falls in bank and mining stocks have dragged the FTSE 100 down a further 3.4% today as global markets continued to struggle.
River & Mercantile's Hugh Sergeant said negative investor sentiment is pushing up equity risk premiums to credit crunch levels despite strong balance sheets among UK companies.
European and Asian stock markets declined sharply in Wednesday trading, mirroring overnight falls in New York, on concerns the US recovery is faltering.
F&C Investments' UK equity head Peter Lees has been moving up the market-cap scale in his £210m UK Alpha fund, upping exposure to FTSE 100 names by 15% since the start of the year.
US and Asian markets fell overnight on fears the US government will fail to resolve its debt crisis, ahead of a crucial vote by the House of Representatives today.