The nine-year old company put out a trading statement on Thursday admitting that profits for the six months ending January 31 would be "significantly below market expectations" and that new business in the UK was much weaker than anticipated.
Investors reacted by pushing YouGov's share price down from 71p at Wednesday's close to as low as 34p on Thursday.
Just before lunchtime today the price was 36.5p, leaving the company with a market value of around £36m, its lowest for some time.
YouGov said its cost base remained within budget and its board believed in maintaining its strategy of investing in new product development.
Nadhim Zahawi, chief executive of YouGov, said: "Online market research will continue to grow as a proportion of research spend and we believe that YouGov is uniquely positioned to meet the demand for accurate, high-quality real-time research.
"We see the recession as further disrupting this industry, which gives us an opportunity to build the leading market research company of tomorrow. We are committed to that vision."
Other company developments last week included the launch of its Recession Tracker website in the UK and its decision to bring all of its international operations together under the YouGov brand.
This will affect overseas acquisitions such as Psychonomics in Germany and Polimetrix in the US.