Sumitomo Mitsui Trust Group Reports 5.0% Passive Stake in Mizuho Financial Group

Executive Summary

On October 29, 2026, Sumitomo Mitsui Trust Group, Inc. filed Amendment No. 5 to Schedule 13G, disclosing beneficial ownership of 121,591,698 shares of Mizuho Financial Group, Inc. Common Stock, representing 5.0% of the class outstanding as of September 30, 2026.

Key Filing Details

• Reporting Entity: Sumitomo Mitsui Trust Group, Inc. (Parent Holding Company / Financial Institution)
• Shares Owned: 121,591,698 shares
• Percent of Class: 5.0%
• Voting Authority:
  • Sole Voting Power: 0
  • Shared Voting Power: 114,648,798
• Dispositive Authority:
  • Sole Dispositive Power: 0
  • Shared Dispositive Power: 121,591,698
• Subsidiaries Involved: Portions of the reported securities are beneficially owned through asset management subsidiaries, including Sumitomo Mitsui Trust Asset Management Co., Ltd. and Amova Asset Management Co., Ltd. (formerly Nikko Asset Management Co., Ltd.).
• Item 5 Checkbox: The filing indicates in Item 5 that ownership has reached 5% or less (classOwnership5PercentOrLess: Y).

Market Impact & Significance

This filing represents routine passive institutional reporting under Rule 13d-1(b). Because the holdings are maintained in the ordinary course of business without activist intent and ownership hovers right at the 5.0% threshold (indicating potential reduction down to or below 5%), the trading significance is rated Low.