A CEO scan be issued shares as long as there is some meaningful consideration involved. If a non-registrant they are subject to the one year holding exemption under Rule 144. They would also be subject to the selling limitation under 144 for officers, directors and affiliates...but it is not difficult for them to flout that if they got creative.
Otherwise the other usual tactics could be at play as you suggest...chief among them being undisclosed affiliates selling.
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