SoftBank's CEO Masayoshi Son, who is also the chairman at Sprint, has been interested in making some acquisitions to better position Sprint. A company that SoftBank bought back in 2013 and attempted to merge with T-Mobile US in 2014, but those talks eventually fell through due to the fact that regulators were not going to approve such a deal. Now that there is a new administration in charge of the US, and the Incentive Auction is now over, carriers are able to start talking to each other about mergers and acquisitions. During the auction, and for about 6 months before that, carriers were not able to talk with each other, due to the auction. As it would make it unfair for other competitors looking to cash in on some spectrum.
After announcing the earnings for SoftBank, which saw some great numbers for the quarter, despite Sprint not doing so well, Son noted that he would love to open up talks with T-Mobile once again about a merger and/or acquisition. Of course, compared to 30 months ago when Sprint and T-Mobile cut off their talks, T-Mobile has grown and is a much larger company than it was the last time these two talked. That means that the price tag for T-Mobile is going to be much higher, analysts have said it could be about 3-4 times as large. But Son did leave the door open for talking with other companies like Comcast and Charter, both of whom want to break into the wireless space as well. T-Mobile is just the most obvious choice for Sprint and SoftBank.
When SoftBank purchased a controlling stake in Sprint, their initial plan was to then purchase a controlling stake in T-Mobile US, and merge them together. As a combined company, they would be able to better take on the giants of AT&T and Verizon, both of whom have twice the number of customers as T-Mobile, who has about 20 million more than Sprint right now. But regulators wouldn't allow that to happen. And now with Trump in charge, it appears that there will be less regulation, and wireless carriers are excited to see what that will lead too.