The Aon Hewitt Managed Fund index, which tracks managed pensions funds, rose by 1.4% in January after equity markets made a strong start to the year.
The index showed a positive return of 14.7% for the whole of 2012.
The consultants said that investors are gaining in confidence again on the back of four years of steadily rising equity markets.
Brian Delaney, senior investment consultant at Aon Hewitt, cautioned that it is becoming increasingly difficult for investors to source profitable investment opportunities.
He said that government bond yields have started to rise and a considerable tightening of credit spreads has already been witnessed.
''Pension schemes that have hedged their overseas currency exposure will have performed better over the month as the euro has continued to strengthen against its major competing currencies,'' he added.