well could be people buyin under 100 shares here and there which wont print on T and S.Or could jus be HILL reppin someones 200 shares and they jus decided to up their order to 15.DF
Someone could have had a sell in at $10 and cancelled the trade. Now shares are not available at $10 and the MM moves because they dont have any shares.
Another possibility is HILL has only a few shares and wants more for them as they found out news is coming