Testifying at a Senate judiciary committee hearing this week on the relationship between hedge fund short sellers and so-called independent analysts, Kim Blickenstaff had a sorry tale to tell.

The chief executive of Biosite, a medical diagnostics group, explained how his company had repeatedly been the victim of massive shorting in its stock, even as it was producing positive news on the research front. His suspicion was that hedge funds were colluding with analysts to produce negative reports, driving down the stock price for the benefit of the funds’ speculative trades.