Who has been buying HEPHAIST Co., Ltd. stock?

5 distinct investors have filed 4 disclosed large-shareholding filings in HEPHAIST Co., Ltd. (6433), most recently on 2026-03-10. 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 HEPHAIST Co., Ltd. have?

HEPHAIST Co., Ltd. has 4 buy-side and 4 sell-side disclosures on record, covering ¥45M ($292K) in total reported value, spanning 2021-06-07 to 2026-03-10.

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.

HEPHAIST Co., Ltd. 6433

Company

ヒーハイスト精工株式会社HEPHAIST Co., Ltd.

Investors

Buys

Total Value

¥45M ($292K)

Avg Return

+733.64%

Last Filing

2026-03-10

HEPHAIST Co., Ltd. (6433) has 4 disclosed large-shareholding filings and 4 disclosed disposals on record, filed by 5 distinct investors. Together those filings cover ¥45M ($292K) in reported transaction value. The earliest filing StockDrifts holds for HEPHAIST Co., Ltd. is dated 2021-06-07; the most recent is 2026-03-10. Across these filings the average return since disclosure is +733.64%, 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
2026-03-10	BUY	unknown	尾崎文彦 FUMIHIKO OZAKI	activist	1.3M	¥1,611	-	¥435M ($2.8M)
2026-03-10	BUY	unknown	尾崎文彦 FUMIHIKO OZAKI	activist	1.0M	¥1,611	-	¥480M ($3.1M)
2026-02-24	SELL	unknown	尾崎浩太 HIROTA OZAKI	activist	1.2M	¥1,720	+22.6%	¥188M ($1.2M)
2026-02-24	BUY	unknown	尾崎浩太 HIROTA OZAKI	activist	1.2M	¥1,720	-	¥178M ($1.1M)
2024-12-17	BUY	Market Buy	青杉一梁 Ichiro Aosugi	strategic	141.4K	¥380	+250.3%	¥32M ($206K)
2024-12-17	BUY	unknown	共通物産株式会社 Common Bussan Co., Ltd.	strategic	138.0K	¥380	-	-
2024-12-17	BUY	Market Buy	共通物産株式会社 Common Bussan Co., Ltd.	strategic	138.0K	¥380	-	-
2024-12-17	BUY	unknown	共有株式会社 Shared Co., Ltd.	strategic	130.0K	¥380	-	-
2024-12-17	SELL	unknown	青杉一梁 Ichiro Aosugi	strategic	15.4K	¥380	-250.3%	¥48M ($310K)
2024-12-17	BUY	Market Buy	共有株式会社 Shared Co., Ltd.	strategic	130.0K	¥380	-	-
2024-10-25	BUY	unknown	青杉一梁 Ichiro Aosugi	strategic	57.3K	¥234	+468.8%	¥13M ($87K)
2024-10-25	BUY	unknown	共通物産株式会社 Common Bussan Co., Ltd.	strategic	138.0K	¥234	+468.8%	¥32M ($208K)
2024-10-25	BUY	unknown	共有株式会社 Shared Co., Ltd.	strategic	130.0K	¥234	+468.8%	¥30M ($196K)
2021-06-07	BUY	unknown	尾崎文彦 FUMIHIKO OZAKI	activist	1.2M	¥491	-	¥36M ($230K)
2021-06-07	BUY	unknown	尾崎浩太 HIROTA OZAKI	activist	1.4M	¥491	-	¥32M ($208K)
2021-06-07	SELL	unknown	尾崎文彦 FUMIHIKO OZAKI	activist	1.2M	¥491	-171.1%	¥36M ($230K)
2021-06-07	SELL	unknown	尾崎浩太 HIROTA OZAKI	activist	1.4M	¥491	-171.1%	¥32M ($208K)
2021-06-07	BUY	unknown	尾崎浩太 HIROTA OZAKI	activist	1.4M	¥491	-	¥35M ($226K)
2021-06-07	BUY	unknown	尾崎文彦 FUMIHIKO OZAKI	activist	1.2M	¥491	-	¥35M ($228K)

Frequently asked questions

Who has been buying HEPHAIST Co., Ltd. stock?: 5 distinct investors have filed 4 disclosed large-shareholding filings in HEPHAIST Co., Ltd. (6433), most recently on 2026-03-10. 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 HEPHAIST Co., Ltd. have?: HEPHAIST Co., Ltd. has 4 buy-side and 4 sell-side disclosures on record, covering ¥45M ($292K) in total reported value, spanning 2021-06-07 to 2026-03-10.
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.