AT&T to Divest America Movil Stake to Carlos Slim

Regional carriers are worth less than national carriers. Mvno's are worth less than regional carriers. So how in the hell is 8.3 % of Tracfone worth 5.6 billion At&t was going to over pay in 2011 for T-mobile 39 billion when it was only worth about 18 billion. My point is how is Tracfone with 25 million customers worth more all in all than T-mobile was in 2011 who had more customers then and a national network>? I understand it says At&t has 24 % voting rights but uh still that rate on that low stake makes no common sense.