Shares of Dynavax Technologies (DVAX) are off nearly 4 percent on Thursday after a huge spike in volume just before noon.

Major Trade Moves Many DVAX Shares in Short Timeframe

There’s no clear indication of where the volume came from, but some 10 million shares moved in a few minutes, constituting more than 80 percent of the day’s volume in early trading. Shares reached the day’s low point during this spike in volume, falling as low as $1.65 a share or down 7.8 percent from yesterday’s close at $1.79 a share.

There is no clear news dictating the move, but it seems possible that a major position was either bought or sold based on the concentration of the volume. This comes one day after an SEC filing by The Vanguard Group revealed ownership of over 7.7 million shares or 2.94 percent of the total float.

Rough 2013 Still Finished Strong

Dynavax is coming off of a disastrous 2013 that saw shares lose nearly 30 percent last year, including a steep drop in February following news that the FDA would require further safety evaluations for the company’s lead product candidate hepatitis B vaccine Hepislav, and another major sell-off following a meeting with the FDA on Jun. 10 of last year.

However, after pricing a public offering that raised some $85.5 million and announcing a new Hepislav safety trial in October, shares rebounded, climbing over 80 percent from early November to mid-January. That momentum was halted after Jan. 17, though, and shares are back down almost 15 percent from that point.

Hepislav Key to DVAX's Future

The future of Dynavax is clearly resting on the shoulders of its lead therapy, Hepislav, and whether or not this next trial can demonstrate its safety. While Dynavax currently has four other treatments in its pipeline, three are only in phase I trials with the fourth still in pre-clinical. The stock has been a favorite of some short sellers, who see the potential for the stock to go to zero if Hepislav fails to get to market.