Omeros Corporation (NASDAQ:OMER) shares tumbled nearly 9% yesterday, following a bearish report issued by Art Doyle research, a group that identifies as having a short position in Omeros’ stock.

“As we will show you in this report, Omeros tried to do subcutaneous delivery in their Phase 1 for OMS721. But at the end they magically added IV. And haven’t looked back since. IV all the way baby. So they will tell you that they have a competitive product but like most everything that seems to come out of their mouth, it isn’t true. Omeros doesn’t have subcutaneous in Phase 2 and they never will. What are they hiding about their Phase I data,” Art Doyle said.

“We went to Mexico. We went to Madrid. We actually have the Omeros phase 2 data that they say is so great for OMS721. Newsflash: It isn’t great! We will show it to you since Omeros won’t. The CEO can try to sue us, but we aren’t your old CFO who called you out on a whistleblower case. You know, the one Omeros paid almost $4 million to settle,” the research group continued.

In response, Omero stated that the report is replete with falsehoods, misleading statements and incorrect analyses and conclusions. “Art Doyle” states that it stands to profit in the event that Omeros’ share price declines. The report is actionable and the company is pursuing legal remedies. Omeros intends to hold all responsible parties accountable.

Shares of Omeros are up nearly 6% to $21.64 in pre-market trading Thursday. OMER has a 1-year high of $27.09 and a 1-year low of $7.20. The stock’s 50-day moving average is $18.33 and its 200-day moving average is $13.73.

On the ratings front, Omeros has been the subject of a number of recent research reports. In a report issued on June 13, Cantor analyst Elemer Piros reiterated a Hold rating on OMER, with a price target of $15, which represents a potential downside of 26% from where the stock is currently trading. Separately, on the same day, Maxim’s Jason McCarthy reiterated a Buy rating on the stock and has a price target of $23.

According to TipRanks.com, which ranks over 7,500 financial analysts and bloggers to gauge the performance of their past recommendations, Elemer Piros and Jason McCarthy have a yearly average loss of -1.3% and -10.3% respectively. Piros has a success rate of 48% and is ranked #3676 out of 4600 analysts, while McCarthy has a success rate of 35% and is ranked #4522.

Omeros Corp. operates as a biopharmaceutical company committed to discovering, developing, and commercializing small-molecule and protein therapeutics for large market as well as orphan indications targeting inflammation, coagulopathies and disorders of the central nervous system.