The Securities and Exchange Surveillance Commission (SESC) on 9 October 2026 recommended that the prime minister and the commissioner of the Financial Services Agency order a ¥1.87mn surcharge on a former Mitsubishi Corporation employee for insider trading in Nagatanien Holdings shares. A recommendation is a step toward an order, not the order itself.
How the information travelled
The release says the person worked for Mitsubishi Corporation and, in the course of those duties, was aware that the decision-making body of Marunouchi Capital had decided to launch a tender offer for Nagatanien. The information arose from Mitsubishi Corporation's negotiation of transaction agreements with entities controlled by Marunouchi Capital and two other parties.
The trades
On 28 and 29 May 2024, ahead of the 3 June 2024 announcement of the tender offer, the person bought 2,000 Nagatanien shares for their own account at a total of about ¥4.4mn. The annex lists seven purchase lots at prices from ¥2,187 to ¥2,212 a share. Nagatanien was delisted on 27 September 2024.
The arithmetic
Under Article 175(2) of the Financial Instruments and Exchange Act, the surcharge is based on the highest price in the two weeks after the announcement, ¥3,133.5, applied to the 2,000 shares, less the amount actually paid. That gives ¥1,871,400, which Article 176(2) rounds down to ¥1,870,000.
The SESC says it used information provided by Japan Exchange Regulation as a reference in establishing the facts.