SoftBank just made $12 billion after Sprint's stock rocketed 70%

SoftBank made about $12 billion after Sprint's stock price rocketed 70% on Tuesday.
The Japanese conglomerate is Sprint's parent, owning nearly 85% of the wireless carrier's shares.
The stock surge boosted the value of SoftBank's holding from about $17 billion to $29 billion.
Sprint's shares shot up after a federal judge approved its mega-merger with T-Mobile.
Visit Business Insider's homepage for more stories.SoftBank made about $12 billion this morning, courtesy of Sprint's surging stock price