In its CFA UK Valuations Index, which is a quarterly survey of UK-based investment professionals, 78% of respondents suggested government bonds are overvalued.
This represents a 6% increase since the same question was asked three months ago, with 43% indicating they were very overvalued and 35% believing them to be somewhat overvalued.
In comparison, only 8% of investment professionals asked through government bonds were undervalued, down from 12% last quarter.
Corporate bonds were also viewed as overvalued by almost half of those surveyed (49%), up from 34% in the first quarter of the year.
Less than one in five now view corporate bonds as undervalued (19%) versus 27% of respondents three months ago.
At the other end of the spectrum, there’s general consensus that equities are undervalued, with only 26% and 24% thinking they are overvalued in developed markets and emerging markets respectively.
Will Goodhart, chief executive of CFA UK, said: "Investment professionals were already concerned about the valuations of government bond markets at the beginning of the year, and their concerns have increased over the last quarter. They now hold the same view in relation to corporate bonds.
"While fixed income securities have been attractive on account of their perceived safe haven status, our survey suggests that they may no longer offer good value relative to other assets on a 12-month time horizon."
