Who has been buying JAPAN MATERIAL Co., Ltd. stock?

11 distinct investors have filed 9 disclosed large-shareholding filings in JAPAN MATERIAL Co., Ltd. (6055), most recently on 2026-02-05. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.

How many insider filings does JAPAN MATERIAL Co., Ltd. have?

JAPAN MATERIAL Co., Ltd. has 9 buy-side and 12 sell-side disclosures on record, covering ¥17.8B ($114.7M) in total reported value, spanning 2021-03-24 to 2026-02-05.

Where does StockDrifts get JAPAN MATERIAL Co., Ltd. insider data?

From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.

Do insider buys in Japanese stocks predict returns?

Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

JAPAN MATERIAL Co., Ltd. 6055

Company

ジャパンマテリアル株式会社JAPAN MATERIAL Co., Ltd.

Investors

Buys

Total Value

¥17.8B ($114.7M)

Avg Return

+2.74%

Last Filing

2026-02-05

JAPAN MATERIAL Co., Ltd. (6055) has 9 disclosed large-shareholding filings and 12 disclosed disposals on record, filed by 11 distinct investors. Together those filings cover ¥17.8B ($114.7M) in reported transaction value. The earliest filing StockDrifts holds for JAPAN MATERIAL Co., Ltd. is dated 2021-03-24; the most recent is 2026-02-05. All of it is parsed from EDINET large-shareholding (5%+) reports, the official disclosure system operated by the Financial Services Agency (Japan). Across these filings the average return since disclosure is +2.74%, measured from each filing date to the latest available close.

Price & insider activity (12 months)

Recent filings

Date	Type	Source	Insider	Purpose	Shares	Price at filing	Return	Value
2026-07-06	SELL	unknown	アモーヴァ・アセットマネジメント株式会社	other	4.4M	¥2,451	+0.8%	¥361M ($2.3M)
2026-07-06	BUY	Market Buy	三井住友トラスト・アセットマネジメント株式会社	other	2.9M	¥2,451	-0.8%	¥3.2B ($20.5M)
2026-06-04	BUY	Market Buy	アモーヴァ・アセットマネジメント株式会社	other	4.5M	¥2,422	+3.2%	¥2.8B ($17.7M)
2026-06-04	SELL	unknown	三井住友トラスト・アセットマネジメント株式会社	other	1.6M	¥2,422	-3.2%	¥2.0B ($12.8M)
2026-02-05	BUY	Market Buy	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	5.8M	¥1,690	+9.3%	¥782M ($5.0M)
2025-09-19	BUY	Market Buy	アモーヴァ・アセットマネジメント株式会社 Amova Asset Management Co., Ltd.	other	2.3M	¥1,906	-3.1%	¥120M ($776K)
2025-09-19	SELL	Market Buy	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	3.1M	¥1,906	+3.1%	¥40M ($259K)
2025-06-04	BUY	negotiated	田中久男 Hisao Tanaka	activist	10.5M	¥1,460	+26.5%	¥15.4B ($99.1M)
2025-06-04	BUY	negotiated	株式会社HT HT Co., Ltd.	activist	7.3M	¥1,460	+26.5%	¥10.7B ($68.8M)
2025-05-21	BUY	unknown	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	3.1M	¥1,441	+28.2%	¥4.5B ($29.1M)
2025-05-21	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	2.2M	¥1,441	+28.2%	¥3.2B ($20.4M)
2025-04-03	BUY	negotiated	田中智和 TOMOKAZU TANAKA	activist	8.8M	¥1,116	+65.5%	¥9.8B ($63.4M)
2025-04-03	BUY	negotiated	T&T株式会社 T&T Co., Ltd.	activist	5.3M	¥1,116	+65.5%	¥5.9B ($38.2M)
2025-01-08	BUY	negotiated	株式会社HT HT Co., Ltd.	activist	7.3M	¥1,844	+0.2%	¥13.5B ($86.8M)
2025-01-08	BUY	negotiated	田中久男 Hisao Tanaka	activist	10.5M	¥1,844	+0.2%	¥19.4B ($125.2M)
2025-01-07	BUY	Market Buy	株式会社HT HT Co., Ltd.	activist	7.3M	¥1,803	+2.4%	¥3.6B ($23.2M)
2025-01-07	SELL	Market Buy	田中久男 Hisao Tanaka	activist	10.5M	¥1,803	-2.4%	¥3.6B ($23.1M)
2024-08-22	SELL	Market Buy	レオス・キャピタルワークス株式会社 RHEOS CAPITAL WORKS Inc.	passive	4.2M	¥1,780	-3.8%	¥2.1B ($13.5M)
2023-06-19	SELL	Market Buy	3Dインベストメント・パートナーズ・プライベート・リミティッド(3D Investment Partners Pte. Ltd.) 3D Investment Partners Pte. Ltd.	passive	5.1M	¥2,371	+22.1%	¥2.8B ($17.9M)
2023-06-07	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.9M	¥2,342	-21.1%	¥8.9B ($57.7M)
2023-06-07	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	45.8K	¥2,342	+21.1%	¥443M ($2.9M)
2023-06-07	BUY	unknown	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	31.7K	¥2,342	-21.1%	¥6.6B ($42.3M)
2022-10-26	SELL	negotiated	田中智和 TOMOKAZU TANAKA	activist	8.8M	¥1,917	+3.6%	¥947M ($6.1M)
2022-10-26	BUY	Market Buy	T&T株式会社 T&T Co., Ltd.	activist	5.3M	¥1,917	-3.6%	¥10.2B ($65.5M)
2022-10-26	BUY	Market Buy	田中智和 TOMOKAZU TANAKA	activist	8.8M	¥1,917	-3.6%	¥1.7B ($11.1M)
2022-10-26	BUY	negotiated	T&T株式会社 T&T Co., Ltd.	activist	5.3M	¥1,917	-3.6%	¥10.2B ($65.5M)
2022-03-23	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	230.9K	¥1,748	+5.7%	¥404M ($2.6M)
2022-03-23	SELL	Market Buy	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	360.8K	¥1,748	-5.7%	¥1.6B ($10.3M)
2022-03-23	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	5.4M	¥1,748	+5.7%	¥1.9B ($12.0M)
2021-12-08	SELL	negotiated	T&T株式会社 T&T Co., Ltd.	activist	5.3M	¥1,768	-4.5%	¥1.2B ($8.0M)
2021-12-08	SELL	negotiated	田中智和 TOMOKAZU TANAKA	activist	9.3M	¥1,768	-4.5%	¥706M ($4.6M)
2021-12-07	SELL	negotiated	株式会社HT HT Co., Ltd.	activist	5.3M	¥1,722	-7.3%	¥1.2B ($7.8M)
2021-12-07	BUY	negotiated	田中久男 Hisao Tanaka	activist	12.5M	¥1,722	+7.3%	¥21.6B ($139.0M)
2021-03-25	BUY	negotiated	株式会社HT HT Co., Ltd.	activist	6.0M	¥1,285.505	+43.7%	¥7.7B ($49.8M)
2021-03-25	BUY	negotiated	株式会社HT HT Co., Ltd.	activist	6.0M	¥1,285.505	+43.7%	¥7.7B ($49.8M)
2021-03-25	SELL	negotiated	田中久男 Hisao Tanaka	activist	12.5M	¥1,285.505	-43.7%	¥2.3B ($14.9M)
2021-03-25	SELL	negotiated	田中久男 Hisao Tanaka	activist	12.5M	¥1,285.505	-43.7%	¥2.3B ($14.9M)
2021-03-24	BUY	negotiated	株式会社HT HT Co., Ltd.	activist	6.0M	¥1,273.217	+45.1%	¥7.6B ($49.3M)
2021-03-24	BUY	negotiated	田中久男 Hisao Tanaka	activist	14.3M	¥1,273.217	+45.1%	¥18.2B ($117.6M)

Frequently asked questions

Who has been buying JAPAN MATERIAL Co., Ltd. stock?: 11 distinct investors have filed 9 disclosed large-shareholding filings in JAPAN MATERIAL Co., Ltd. (6055), most recently on 2026-02-05. Each filer, their role, the number of shares and the price at filing are listed in the table on this page.
How many insider filings does JAPAN MATERIAL Co., Ltd. have?: JAPAN MATERIAL Co., Ltd. has 9 buy-side and 12 sell-side disclosures on record, covering ¥17.8B ($114.7M) in total reported value, spanning 2021-03-24 to 2026-02-05.
Where does StockDrifts get JAPAN MATERIAL Co., Ltd. insider data?: From EDINET large-shareholding (5%+) reports — the official filing system run by the Financial Services Agency (Japan). StockDrifts parses each disclosure and matches it to daily price history; the original filings remain available directly from EDINET.
Do insider buys in Japanese stocks predict returns?: Not uniformly. StockDrifts scored 101,000+ Japanese large-shareholding filings on fixed 12-month forward returns and found the predictive power concentrated in specific filer types and filing patterns rather than spread evenly across all disclosures.

Source filings

Every trade listed above is disclosed in EDINET large-shareholding (5%+) reports, filed with the Financial Services Agency (Japan). View the original EDINET filings for JAPAN MATERIAL Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.