Who has been buying Koatsu Kogyo Co.,Ltd. stock?

7 distinct investors have filed 7 disclosed large-shareholding filings in Koatsu Kogyo Co.,Ltd. (1743), most recently on 2025-09-19. 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 Koatsu Kogyo Co.,Ltd. have?

Koatsu Kogyo Co.,Ltd. has 7 buy-side and 2 sell-side disclosures on record, covering ¥307M ($2.0M) in total reported value, spanning 2022-01-06 to 2025-09-19.

Where does StockDrifts get Koatsu Kogyo 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.

Koatsu Kogyo Co.,Ltd. 1743

Company

コーアツ工業株式会社Koatsu Kogyo Co.,Ltd.

Investors

Buys

Total Value

¥307M ($2.0M)

Avg Return

+11.57%

Last Filing

2025-09-19

Koatsu Kogyo Co.,Ltd. (1743) has 7 disclosed large-shareholding filings and 2 disclosed disposals on record, filed by 7 distinct investors. Together those filings cover ¥307M ($2.0M) in reported transaction value. The earliest filing StockDrifts holds for Koatsu Kogyo Co.,Ltd. is dated 2022-01-06; the most recent is 2025-09-19. 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 +11.57%, 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
2025-09-19	BUY	unknown	株式会社日本地下技術 NIHONCHIKAGIJUTSU	other	127.4K	¥1,820	+0.1%	¥232M ($1.5M)
2025-09-19	BUY	unknown	株式会社南日本運輸建設 MINAMINIHONUNYUKENSETSU	other	148.4K	¥1,820	+0.1%	¥270M ($1.7M)
2025-09-19	BUY	unknown	株式会社ガイアテック GAIATEC	strategic	203.6K	¥1,820	+0.1%	¥371M ($2.4M)
2025-09-19	BUY	unknown	株式会社植村組 UEMURAGUMI	other	203.7K	¥1,820	+0.1%	¥371M ($2.4M)
2025-09-19	SELL	unknown	コーアツ工業共栄会理事長水迫繁一 Koatsu Kogyo's Kyoeikai Assn, Shigeichi Mizusoko	unknown	0	¥1,820	-0.1%	¥337M ($2.2M)
2025-09-19	BUY	unknown	株式会社ウエムラ Uemura Co., Ltd.	activist	1.2M	¥1,820	+0.1%	¥2.2B ($14.3M)
2025-09-09	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	203.6K	¥1,836	-0.8%	¥374M ($2.4M)
2025-09-09	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	678.8K	¥1,836	-0.8%	¥1.2B ($8.0M)
2025-09-05	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	678.8K	¥1,839	-0.9%	¥1.2B ($8.1M)
2025-08-21	BUY	unknown	株式会社日本地下技術 NIHONCHIKAGIJUTSU	other	127.4K	¥1,842	-1.1%	¥235M ($1.5M)
2025-08-21	BUY	unknown	株式会社植村組 UEMURAGUMI	other	203.7K	¥1,842	-1.1%	¥375M ($2.4M)
2025-08-21	BUY	unknown	株式会社南日本運輸建設 MINAMINIHONUNYUKENSETSU	other	148.4K	¥1,842	-1.1%	¥273M ($1.8M)
2025-08-12	BUY	unknown	株式会社日本地下技術 NIHONCHIKAGIJUTSU	other	127.4K	¥1,852	-1.6%	¥236M ($1.5M)
2025-08-12	BUY	unknown	株式会社日本地下技術 NIHONCHIKAGIJUTSU	other	42.5K	¥1,852	-1.6%	¥79M ($508K)
2025-08-12	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	203.6K	¥1,852	-1.6%	¥377M ($2.4M)
2025-08-12	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	678.8K	¥1,852	-1.6%	¥1.3B ($8.1M)
2025-08-12	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	203.6K	¥1,852	-1.6%	¥377M ($2.4M)
2025-08-12	BUY	negotiated	株式会社ガイアテック GAIATEC	strategic	678.8K	¥1,852	-1.6%	¥1.3B ($8.1M)
2025-08-12	BUY	unknown	株式会社南日本運輸建設 MINAMINIHONUNYUKENSETSU	other	148.4K	¥1,852	-1.6%	¥275M ($1.8M)
2025-08-12	BUY	unknown	株式会社南日本運輸建設 MINAMINIHONUNYUKENSETSU	other	49.5K	¥1,852	-1.6%	¥92M ($591K)
2025-08-12	BUY	unknown	株式会社植村組 UEMURAGUMI	other	203.7K	¥1,852	-1.6%	¥377M ($2.4M)
2025-08-12	BUY	unknown	株式会社植村組 UEMURAGUMI	other	67.9K	¥1,852	-1.6%	¥83M ($538K)
2025-08-12	BUY	unknown	株式会社植村組 UEMURAGUMI	other	112.9K	¥1,852	-1.6%	¥209M ($1.3M)
2025-08-12	BUY	unknown	株式会社植村組 UEMURAGUMI	other	1.1M	¥1,852	-1.6%	¥2.1B ($13.5M)
2025-08-12	BUY	unknown	株式会社植村組 UEMURAGUMI	other	67.9K	¥1,852	-1.6%	¥126M ($811K)
2025-07-29	BUY	Market Buy	コーアツ工業共栄会理事長水迫繁一 Koatsu Kogyo's Kyoeikai Assn, Shigeichi Mizusoko	strategic	184.8K	¥1,631	+11.7%	¥37M ($240K)
2022-08-17	SELL	unknown	松澤孝一 KOICHI MATSUZAWA	other	26.2K	¥1,803.33	-1.0%	¥84M ($539K)
2022-01-06	BUY	Market Buy	コーアツ工業共栄会理事長石堂和雄 Koatsu Kogyo's Kyoeikai Assn, Kazuo Ishido	strategic	54.0K	¥1,080	+68.7%	¥9M ($57K)

Frequently asked questions

Who has been buying Koatsu Kogyo Co.,Ltd. stock?: 7 distinct investors have filed 7 disclosed large-shareholding filings in Koatsu Kogyo Co.,Ltd. (1743), most recently on 2025-09-19. 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 Koatsu Kogyo Co.,Ltd. have?: Koatsu Kogyo Co.,Ltd. has 7 buy-side and 2 sell-side disclosures on record, covering ¥307M ($2.0M) in total reported value, spanning 2022-01-06 to 2025-09-19.
Where does StockDrifts get Koatsu Kogyo 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 Koatsu Kogyo Co.,Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.