The Singapore-based activist fund Effissimo Capital Management has quietly become Tamron’s top shareholder, surpassing longtime holder Sony Group Corporation:
According to EDINET filings and Japanese reports, Effissimo Capital Management has increased its stake to 17.38% (29,691,800 shares) as of late March 2026. Sony remains at 15.35% (25,038,000 shares, unchanged from the end of 2025). Tamron’s official IR page still shows the year-end figures, but large-shareholding reports confirm Effissimo has crossed ahead:
| Shareholder | Stake | Shares |
|---|---|---|
| Effissimo Capital Management (ECM) | 17.38% | 29,691,800 |
| Sony Group Corporation | 15.35% | 25,038,000 |
| Master Trust Bank of Japan (trust) | ~10.3% | — |
Effissimo has steadily built its position over the past year (from ~10.8% in late 2025), filing multiple increases. Here is the recent Effissimo accumulation path (approximate, from filings):
Effissimo is a Singapore-based activist investor known for its stakes in Japanese companies such as Nissan and Toshiba. Sony’s stake has remained static at the year-end figure. Tamron executed a 4-for-1 stock split in July 2025, but the percentages above reflect the current post-split reality in recent reports.
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Via dclife
