If you can get $6/share for Sprint (S) today, grab it.
I've covered Son for over 20 years, however, and if you're expecting him to make you money you will be in for a wild ride.
Son is a sort of Japanese version of Richard Branson, only with more brass and a poorer track record. He was in publishing early in the 1990s, bought Comdex from Sheldon Adelson in the middle of the 1990s, then lost an estimated $70 billion in the dot-bomb, somehow coming out the other side as a broadband ISP. He then bought Vodafone's Japanese arm, put the Softbank name on it (it's like the name Virgin to Branson) and his baseball team won the Japan Series in 2011. After the Fukushima earthquake he announced grand plans to expand the country's use of solar power, which have so far come to nothing.
Son has been up and down and up and down again. Softbank owns the biggest part of Yahoo Japan, which also includes access services as well as the Web site, but Yahoo (YHOO) itself still holds a big stake, and while there have been talks about Softbank buying out Yahoo nothing has yet been agreed to.
What Son really wants is Clearwire (CLWR), in which Sprint has a stake, because the technology it's using could become part of a global standard in fast wireless broadband. Son sees himself running the first global wireless brand, he probably sees the yen as overvalued, and putting Softbank assets into dollars thus makes sense to him at this time.
Prices like $19 billion are being talked about but Son needs to hold back some financial capacity in order to build-out Clearwire's network.
If Son can get all this done, it would be great for customers. He's already testing out a 110 Mbps wireless router in Japan, selling 5 GB of traffic for just $64/month. But he's going to be stretching his finances to the limit, he has failed at big things before, and you have to be skeptical.
Second-tier wireless companies like Sprint, Metro PCS (PCS) and T-Mobile have been consolidating and looking for bids for years, because capital costs are so difficult to recoup in a competitive market. It's easy to see Son as the "greater fool" coming in with a big wad of cash, high hopes, and good luck to you.
If you have some Sprint today, count yourself lucky.