Who has been buying Union Tool Co. stock?

5 distinct investors have filed 6 disclosed large-shareholding filings in Union Tool Co. (6278), most recently on 2026-04-16. 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 Union Tool Co. have?

Union Tool Co. has 6 buy-side and 6 sell-side disclosures on record, covering ¥11.9B ($76.6M) in total reported value, spanning 2021-11-09 to 2026-04-16.

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.

Union Tool Co. 6278

Company

ユニオンツール株式会社Union Tool Co.

Investors

Buys

Total Value

¥11.9B ($76.6M)

Avg Return

+313.85%

Last Filing

2026-04-16

Union Tool Co. (6278) has 6 disclosed large-shareholding filings and 6 disclosed disposals on record, filed by 5 distinct investors. Together those filings cover ¥11.9B ($76.6M) in reported transaction value. The earliest filing StockDrifts holds for Union Tool Co. is dated 2021-11-09; the most recent is 2026-04-16. Across these filings the average return since disclosure is +313.85%, 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
2026-06-04	SELL	unknown	野村證券株式会社	other	6.5K	¥22,700	+41.0%	¥9.9B ($64.0M)
2026-06-04	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	390.2K	¥22,700	+41.0%	¥1.8B ($11.3M)
2026-06-04	BUY	unknown	ノムラセキュリテーズインターナショナル NOMURA SECURITIES INTERNATIONAL,Inc.	other	0	¥22,700	-	-
2026-06-04	BUY	Market Buy	野村アセットマネジメント株式会社	other	285.0K	¥22,700	-41.0%	¥90M ($579K)
2026-05-21	BUY	unknown	野村證券株式会社	other	442.4K	¥19,390	-30.9%	¥8.6B ($55.3M)
2026-05-21	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	466.0K	¥19,390	-30.9%	¥9.0B ($58.3M)
2026-05-21	BUY	unknown	ノムラセキュリテーズインターナショナル NOMURA SECURITIES INTERNATIONAL,Inc.	other	0	¥19,390	-30.9%	-
2026-05-21	BUY	unknown	野村アセットマネジメント株式会社	other	281.2K	¥19,390	-30.9%	¥5.5B ($35.2M)
2026-04-16	BUY	unknown	片山貴雄	strategic	593.4K	¥17,300	-	-
2026-04-16	BUY	unknown	株式会社晃永	strategic	6.1M	¥17,300	-	-
2026-04-16	BUY	unknown	公益財団法人ユニオンツール育英奨学会	strategic	1.0M	¥17,300	-	-
2025-03-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	795.6K	¥4,255	-214.7%	¥909M ($5.9M)
2024-11-22	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	1.0M	¥5,240	+155.5%	¥5.3B ($34.1M)
2023-09-15	BUY	unknown	片山貴雄 takao katayama	strategic	593.1K	¥3,690	-	-
2023-09-15	BUY	unknown	株式会社晃永 Akinaga Co., Ltd.	strategic	6.1M	¥3,690	-	-
2023-09-15	BUY	unknown	公益財団法人ユニオンツール育英奨学会 Union Tool Scholarship Foundation	strategic	1.0M	¥3,690	-	-
2023-09-15	BUY	unknown	ミクロファイン株式会社 Micro Fine Co., Ltd.	strategic	19.7K	¥3,690	+262.9%	¥6.5B ($41.8M)
2022-03-18	BUY	unknown	株式会社晃永 Akinaga Co., Ltd.	strategic	6.1M	¥3,720	-	-
2022-03-18	SELL	unknown	ミクロファイン株式会社 Micro Fine Co., Ltd.	strategic	224.3K	¥3,720	-259.9%	¥736M ($4.7M)
2022-03-18	BUY	unknown	片山貴雄 takao katayama	strategic	592.9K	¥3,720	-	-
2022-03-18	BUY	unknown	公益財団法人ユニオンツール育英奨学会 Union Tool Scholarship Foundation	strategic	1.0M	¥3,720	-	-
2021-11-09	SELL	unknown	片山貴雄 takao katayama	strategic	592.8K	¥3,845	-248.2%	¥114M ($736K)
2021-11-09	SELL	unknown	片山貴雄 takao katayama	strategic	592.8K	¥3,845	-248.2%	¥114M ($736K)
2021-11-09	BUY	Market Buy	片山貴雄 takao katayama	strategic	623.2K	¥3,845	+248.2%	¥122M ($785K)
2021-11-09	BUY	Market Buy	株式会社晃永 Akinaga Co., Ltd.	strategic	6.1M	¥3,845	+248.2%	¥1.1B ($7.4M)
2021-11-09	BUY	Market Buy	公益財団法人ユニオンツール育英奨学会 Union Tool Scholarship Foundation	strategic	1.0M	¥3,845	+248.2%	¥190M ($1.2M)
2021-11-09	BUY	Market Buy	ミクロファイン株式会社 Micro Fine Co., Ltd.	strategic	590.1K	¥3,845	+248.2%	¥106M ($687K)
2021-11-09	BUY	unknown	株式会社晃永 Akinaga Co., Ltd.	strategic	6.1M	¥3,845	-	-
2021-11-09	BUY	unknown	公益財団法人ユニオンツール育英奨学会 Union Tool Scholarship Foundation	strategic	1.0M	¥3,845	-	-
2021-11-09	SELL	unknown	ミクロファイン株式会社 Micro Fine Co., Ltd.	strategic	421.4K	¥3,845	-248.2%	¥646M ($4.2M)
2021-11-09	BUY	unknown	株式会社晃永 Akinaga Co., Ltd.	strategic	6.1M	¥3,845	-	-
2021-11-09	BUY	unknown	公益財団法人ユニオンツール育英奨学会 Union Tool Scholarship Foundation	strategic	1.0M	¥3,845	-	-
2021-11-09	SELL	unknown	ミクロファイン株式会社 Micro Fine Co., Ltd.	strategic	421.4K	¥3,845	-248.2%	¥646M ($4.2M)

Frequently asked questions

Who has been buying Union Tool Co. stock?: 5 distinct investors have filed 6 disclosed large-shareholding filings in Union Tool Co. (6278), most recently on 2026-04-16. 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 Union Tool Co. have?: Union Tool Co. has 6 buy-side and 6 sell-side disclosures on record, covering ¥11.9B ($76.6M) in total reported value, spanning 2021-11-09 to 2026-04-16.
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.