Do not fret much about half million shares on either ask or bid.
Big moves come by the millions traded not hundreds of thousands.

Also such volumes do not influence price by much or for long.

I suspect it is just 'day' traders ( ok perhaps monthly ones) taking in some profits on top of most of past year being in the 25 cent range where they likely accumulated a bunch. It is a good bet that anyone offering to sell half million shares today is probably sitting on ten times as many shares. Selling a few now to hedge against a pull back of 5 or 10 cents, to be ready to buy back.
We waiting for news, if we do not get it soon then it is a pruden action to hedge on potential movemets in both directions.

Ed