Funnily enough I did a back-of-the-envelope calculation earlier...

Funnily enough I did a back-of-the-envelope calculation earlier today regarding this, and worked out that if the majority of the turnover is going to the same buyer, they would've picked up somewhere in the order of 35-40m shares since I became a holder in late August, and around 45-50m since the beginning of July. Also, if there is a deal going on behind the scenes, whoever is buying would probably want to keep their holdings under 5% of the float (about 160m shares) until the deal is done, in order to stay under the 5% substantial holder threshold and thus avoid reporting requirements.