Just out right manipulation buy the traders the last couple weeks. You see a bid today at 3.05 and the ask at 3.06 then all of a sudden some buying comes in slapping the ask & it rises to 3.14 and the bid rides up along with the ask. THEN, the ask still at 3.14 the bid starts a drop down to 3.12 then 3.10 while the ask is still 3.14. Here's where the traders force the ask to drop with this 4 cent spread. Therefore the ask is forced back down to 3.10 and so on and so on. Watch once the spread of the bid/ask grows this will start all over again. It's shear manipulation to stop the rise of shares.
Maybe it's gilead or other big pharma's, (probably not) forcing this spread so traders can again bring down shares. Eventually we will break out of this pattern when substantial catalysts are made public GLTA