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Kenneth A. Siegel

Partner | Tokyo


ARM Holdings plc in its $5.2 billion initial public offering and listing on Nasdaq. The IPO is the largest global IPO in 2023 (as of September 2023).

SoftBank in its $280 million Series E investment in Mapbox, an AI-powered location services platform fueling navigation technology used by Toyota, General Motors and BMW.

The board of Toshiba in its $15 billion take-private, the largest take private transaction in Japanese history.

Represented SoftBank in its sale of 90.01% stake in Fortress, a global investment manager with over $45 billion in assets under management, to Mubadala.

Represents SoftBank in its pending $375 million acquisition of Berkshire Grey, Inc. (Nasdaq: BGRY), a robotic automation company, as well as interim financing through the completion of the merger.

Represented SoftBank Group Corp., Sprint’s controlling shareholder, on the landmark merger of Sprint and T-Mobile US, Inc. The total implied enterprise value for Sprint is approximately $59 billion and the aggregate implied enterprise value for the combined company in the all-stock transaction is approximately $146 billion.

Represented SoftBank in its £24.3 billion ($31.4 billion) acquisition of UK-based semiconductor and software design company ARM Holdings. The transaction was the largest-ever cross-border acquisition by a Japanese company (and the largest-ever cash acquisition of a UK company).

Represented SoftBank in its $21.6 billion acquisition of a 78% interest in U.S. wireless operator Sprint. The transaction was the largest U.S. M&A transaction of 2012 and, when announced, the largest cross-border acquisition by a Japanese company (now second to SoftBank’s acquisition of ARM Holdings in 2016).

Represented Toshiba Corporation in the $18 billion sale of its wholly owned subsidiary Toshiba Memory Corporation to a consortium led by Bain Capital, the largest private equity deal ever undertaken in Asia.

Represented SoftBank in its $7.7 billion primary and secondary investment as part of a $9.3 billion sale of stock by Uber. This is the largest-ever private secondary transaction in the technology space.