Who has been buying Ishihara Sangyo Kaisha,Ltd. stock?

6 distinct investors have filed 8 disclosed large-shareholding filings in Ishihara Sangyo Kaisha,Ltd. (4028), most recently on 2025-05-13. 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 Ishihara Sangyo Kaisha,Ltd. have?

Ishihara Sangyo Kaisha,Ltd. has 8 buy-side and 4 sell-side disclosures on record, covering ¥9.3B ($60.0M) in total reported value, spanning 2022-09-22 to 2025-05-13.

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.

Ishihara Sangyo Kaisha,Ltd. 4028

Company

石原産業株式会社Ishihara Sangyo Kaisha,Ltd.

Investors

Buys

Total Value

¥9.3B ($60.0M)

Avg Return

+99.23%

Last Filing

2025-05-13

Ishihara Sangyo Kaisha,Ltd. (4028) has 8 disclosed large-shareholding filings and 4 disclosed disposals on record, filed by 6 distinct investors. Together those filings cover ¥9.3B ($60.0M) in reported transaction value. The earliest filing StockDrifts holds for Ishihara Sangyo Kaisha,Ltd. is dated 2022-09-22; the most recent is 2025-05-13. Across these filings the average return since disclosure is +99.23%, 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
2025-05-13	SELL	unknown	株式会社MI2 MI2 Ltd.	activist	160.6K	¥1,761	-64.6%	¥498M ($3.2M)
2025-05-13	SELL	unknown	村上貴輝 Takateru Murakami	activist	1.4M	¥1,761	-64.6%	¥284M ($1.8M)
2024-04-19	BUY	Market Buy	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	291.9K	¥1,773	+63.5%	¥93M ($601K)
2024-04-19	BUY	Market Buy	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	1.5M	¥1,773	+63.5%	¥2.6B ($16.6M)
2024-03-26	BUY	unknown	株式会社MI2 MI2 Ltd.	activist	445.0K	¥1,699	+70.6%	¥756M ($4.9M)
2024-03-26	BUY	unknown	村上貴輝 Takateru Murakami	activist	1.6M	¥1,699	+70.6%	¥2.7B ($17.5M)
2023-08-03	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	1.9M	¥1,329	+118.1%	¥2.5B ($16.1M)
2023-08-03	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	238.0K	¥1,329	+118.1%	¥316M ($2.0M)
2023-07-21	SELL	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	1.2M	¥1,323	-119.0%	¥363M ($2.3M)
2023-07-21	SELL	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	506.8K	¥1,323	-119.0%	¥171M ($1.1M)
2022-09-22	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	1.4M	¥1,049	+176.3%	¥1.5B ($9.8M)
2022-09-22	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	635.3K	¥1,049	+176.3%	¥666M ($4.3M)

Frequently asked questions

Who has been buying Ishihara Sangyo Kaisha,Ltd. stock?: 6 distinct investors have filed 8 disclosed large-shareholding filings in Ishihara Sangyo Kaisha,Ltd. (4028), most recently on 2025-05-13. 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 Ishihara Sangyo Kaisha,Ltd. have?: Ishihara Sangyo Kaisha,Ltd. has 8 buy-side and 4 sell-side disclosures on record, covering ¥9.3B ($60.0M) in total reported value, spanning 2022-09-22 to 2025-05-13.
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.

More on this data

Every trade listed above comes from an official regulatory disclosure. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.