What happened

Shares of Aptinyx (NASDAQ:APTX), a clinical-stage biotech focused on the brain and nervous system, rose about 27% on Friday.

So what

The double-digit jump appears to be linked to the filing of an SEC document that shows that Adams Street Partners -- an investment management company with $40 billion in assets -- has acquired more than 5 million shares of Aptinyx's stock. That position represents more than 11% of shares outstanding.

Scientist in lab working with instruments

Image source: Getty Images.

Traders bid up the share price in response to the big vote of confidence from Adams Street Partners. 

Now what

Aptinyx's pipeline boasts three drugs that are in phase 2 development as possible treatments for diabetic neuropathy, fibromyalgia, post-traumatic stress disorder, and Parkinson's disease. These are all big indications with huge unmet medical needs, so success in any of them would be a financial windfall for Aptinyx. Adams Street Partners clearly believes that Aptinyx's pipeline holds a lot promise.

It's still unclear whether any of Aptinyx's drugs will make it to market, which is exactly why investing in clinical-stage biotechnology stocks is so difficult. Given the risks, my plan is to follow Aptinyx with great interest from the safety of the sidelines.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.