As i have mentioned a few times over the last week or so, the way to drive the flippers and game players out is with continued buying pressure on the ask. Continued buying pressure on the ask will allow the flippers to sell their shares, but not be able to get back in at a lower price as buying dries up. HNSS has traded in the range it has for the last week or so because buying pressure ebates and allows the flippers and game players to move in and take the pps down and then we repeat the cycle. The only way to break the cycle is steady buying pressure on the ask continueing. JMHO
Decreasing the O/S doesn't prohibit an increase in the tradeable float. However, I think your explanation to be more-likely. Flipping is the likely culprit. However, that large seller you mention could be an insider dumping their previously restricted shares thus diluting the tradable float.