Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Arrowhead Research (NASDAQ:ARWR), a clinical-stage biopharmaceutical company focused on developing RNA-interference-based therapies, rose as much as 15% after announcing that it had completed enrollment in the first cohort of its phase 2a study involving its most exciting drug candidate, ARC-520, for the treatment of chronic hepatitis B.

So what: According to Arrowhead Research's press release, Arrowhead completed enrolling its first eight patients, which should be dosed in just over a week, with the second cohort of eight patients expected to be dosed in May. CEO Christopher Anzalone anticipates releasing top-line results from its phase 2a study sometime in the third quarter. The study itself will "evaluate the depth and duration of hepatitis B surface antigen decline, among other measrues, in response to a single dose of ARC-520." It's believed that reducing hepatitis B surface antigens is the key to providing a functional cure for the disease which currently affects 240 million people worldwide according to the World Health Organization.

Now what: Following a big swoon in over the past two weeks today's move higher appears to be a combination of a rebound from the prior week's negativity, as well as the fact that Arrowhead remains on track to deliver its top-line data by the third quarter. I'm still of the opinion that investors here have been counting their chickens before they're hatched considering that Arrowhead's pipeline is predominantly comprised of early stage or preclinical studies. With a valuation again closing in on three-quarters of a billion dollars, I would much rather stick to the sidelines until we have more concrete data to work with.