State Street Corporation is acquiring Mizuho Financial Group’s global custody business outside Japan in a deal that will transfer approximately $580 billion in assets under custody to the U.S. financial services giant.
The transaction encompasses Mizuho’s custody operations through subsidiaries in Luxembourg and the United States, which currently manage $24 billion in assets under administration alongside the larger custody portfolio. The deal excludes Mizuho’s domestic Japanese custody business, where the bank will continue serving local clients.
State Street executives pointed to the acquisition as evidence of their commitment to growth in Japan, Luxembourg and the U.S. markets. The company already maintains a significant presence in Japan with over 500 employees split between Tokyo and Fukuoka, where it operates a regional service center.
For Mizuho, the divestiture represents a strategic retreat from global custody services, with the bank acknowledging that institutional investors now require custodians with substantial scale. Going forward, Mizuho plans to focus on its domestic Japanese business while partnering with State Street for international custody needs.
The transaction, expected to close by Q4 2025 pending regulatory approvals, will integrate Mizuho’s client base into State Street’s platform, which currently manages $46.6 trillion in assets under custody and administration globally. State Street’s head of Japan indicated the added scale would allow for expanded technology capabilities to serve both existing and newly acquired clients.
