https://www.cnbc.com/2018/06/07/u-s-justice-dept-probes-t-mobile-sprint-merger-effect.html

The U.S. Department of Justice is examining how the proposed merger between T-Mobile US and Sprint could affect prices for smaller wireless operators, according to two people familiar with the matter.

A T-Mobile and Sprint merger would eliminate competition between the two carriers that have been the dominant players in selling network access to wireless companies that often serve pre-paid or price-conscious consumers, and could lead to higher prices for those users.