Japan Post Bank to Acquire Near-20% Stake in Matsui Securities in Broad Strategic Alliance
Japan Post Bank has agreed to acquire a 19.99% voting stake in Matsui Securities, positioning the postal banking giant as the online brokerage’s largest shareholder as part of a wide-ranging capital and business partnership.
Under the terms of an off-market private transaction, Japan Post Bank will purchase 51,489,700 common shares—representing 19.86% of issued stock—from Maruroku, the asset management vehicle of Matsui’s founding family. The founding family had approached Matsui in early 2026 regarding the potential divestment of an approximate 20% holding, prompting the brokerage to search for a strategic partner capable of driving sustainable, long-term expansion while preserving its managerial autonomy.
The alliance establishes a major bridge between Japan Post Bank’s retail reach—comprising roughly 120 million customer accounts and a nationwide branch and digital network—and Matsui’s digital brokerage platform. Through customer referrals and joint marketing initiatives, Matsui aims to capture active investors and high-net-worth clients seeking a shift from traditional face-to-face banking to online trading.
For Japan Post Bank, which has sought to bolster its retail securities capabilities, the transaction provides direct access to Matsui’s seasoned individual investor base. Japan Post Bank intends to utilize Matsui's distribution channels to offer specialized asset management and alternative investment products structured by its subsidiary, Japan Post Bank Asset Management. Additionally, the asset management arm will introduce Matsui as an underwriting syndicate member for initial public offerings (IPOs) stemming from its venture capital portfolio companies.
Corporate governance covenants established alongside the equity purchase emphasize operational continuity. Japan Post Bank has committed to maintaining Matsui's independent management and existing stock exchange listing. As long as Japan Post Bank maintains a voting share of at least 15%, it will hold the right to nominate one non-executive director to Matsui’s board.
The agreement also includes anti-dilution and transfer controls: Japan Post Bank must obtain prior written consent from Matsui before transferring or acquiring additional shares, while Matsui must secure Japan Post Bank's consent for equity issuances that would dilute its voting power. Should the bank's stake fall below 20% due to the exercise of share options or other corporate events, it retains the right to purchase shares in the open market to restore its 20% holding.
The capital and business partnership is scheduled to formally launch on December 28, 2026. Matsui indicated that the transaction will have a minor impact on its financial results for the fiscal year ending March 31, 2027.
Norbert Gehrke
