It seems like the majority of the sales below the previous ask right now are for a very small number of shares like as low as 5000 in some cases. This is obviously an attempt by someone to scare people and drive the price down so they can pickup a big load when they create panic at a low price.
The problem is that unless you specify "All or None" on your buy order, your buy order will be filled with some of these small blocks of shares as a partial fill making you pay a trade fee for each one. That can make you pay twice your offer for these small blocks of shares.
We need to get rid of these small blocks of shares because they are artificially dragging the price down, but we also don't want to pay a ~$9 fee to buy only $5 in shares to clear them out.
News 
Market Data 
Discover 
