Ever since the Government announced that they would allow the entry of a fourth telco, share prices of the 3 existing telcos have been on a down trend. In Dec 2016, the name of the fourth telco was made known; it would be TPG Telecom. Do investors of the 3 telcos need to fear the fourth telco?   Firstly, some background information about TPG. TPG is the second largest internet service provider and the largest mobile virtual network operator (MVNO) in Australia. As a MVNO, it is able to offer the full suite of mobile telco services such as voice, SMS and data. However, there are important differences between a MVNO and a full-scale telco operator such as the 3 local telcos. MVNOs buy network capacity from full-scale telcos and resell them to retail customers. In the case of TPG, it buys network capacity from Vodafone. Thus, when customers use TPG's ......