SoftBank's slide leaves it worth less than holding in Alibaba

SoftBank Group Corp. tumbled below the value of its stake in Alibaba Group Holding Ltd. amid growing concerns about the Japanese company's other assets, including struggling U.S. wireless carrier Sprint Corp. SoftBank's market capitalization fell to 5.46 trillion yen ($46.7 billion) after a four-day stock slide triggered by rising pessimism about Sprint's ability to pay down debt. The Tokyo-based company's stake in Alibaba is worth about $55 billion, according to its own website.

Billionaire Masayoshi Son has struggled to turn around Sprint since buying a controlling stake in 2013 for SoftBank's biggest acquisition ever. The wireless operator lost its place as the third-largest U.S. carrier to T-Mobile US Inc. and its stock this week fell to the lowest level in more than two years and its bonds led declines among junkrated debt Wednesday.

"It's symbolic because it tells you that investors feel SoftBank has been destroying value," said Amir Anvarzadeh, a manager of Japanese equity sales at BGC Partners Inc. in Singapore. "Son's pride has been another major issue, which pushed him to where he is now." In 2013, SoftBank paid $22 billion for a controlling stake Sprint before later acquiring more stock. Its investment in the Overland Park, Kansasbased carrier is now worth about $8.1 billion, according to its website.

At the time of the initial deal, Son touted the potential role for Sprint as he pursued his 300-year plan for SoftBank and goal of building an Internet empire unrivaled in "profit, cash flow and market value."