OK that could be whats going on, sure. Seems according to the 3b on 11 May that the shares were escrowed for 12 months. So their could be a tax benefit (50% tax discount if held for 12 mths) for the holder by selling a few now.
Is there a Top 20 available for TNO right now?. A comparison to prev Top 20's would tell us who at the top is offloading or buying ... if any.