Who has been buying Nakanishi Mfg. Co., Ltd. stock?

11 distinct investors have filed 15 disclosed large-shareholding filings in Nakanishi Mfg. Co., Ltd. (5941), most recently on 2026-03-24. 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 Nakanishi Mfg. Co., Ltd. have?

Nakanishi Mfg. Co., Ltd. has 15 buy-side and 7 sell-side disclosures on record, covering ¥4.5B ($29.1M) in total reported value, spanning 2021-08-10 to 2026-03-24.

Where does StockDrifts get Nakanishi Mfg. 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.

Nakanishi Mfg. Co., Ltd. 5941

Company

株式会社中西製作所Nakanishi Mfg. Co., Ltd.

Investors

Buys

Total Value

¥4.5B ($29.1M)

Avg Return

+67.30%

Last Filing

2026-03-24

Nakanishi Mfg. Co., Ltd. (5941) has 15 disclosed large-shareholding filings and 7 disclosed disposals on record, filed by 11 distinct investors. Together those filings cover ¥4.5B ($29.1M) in reported transaction value. The earliest filing StockDrifts holds for Nakanishi Mfg. Co., Ltd. is dated 2021-08-10; the most recent is 2026-03-24. 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 +67.30%, 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
2026-08-07	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	531.5K	¥2,668	-1.9%	¥207M ($1.3M)
2026-06-18	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	608.9K	¥2,515	-3.2%	¥160M ($1.0M)
2026-03-24	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	673.1K	¥2,585	+1.7%	¥166M ($1.1M)
2025-08-28	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	737.1K	¥2,429	-4.6%	¥153M ($988K)
2025-07-07	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	800.3K	¥2,455	-3.5%	¥286M ($1.8M)
2025-05-28	BUY	Market Buy	中西一真 NAKANISHI KAZUMA	activist	612.8K	¥2,343	+8.4%	¥148M ($953K)
2025-05-28	BUY	Market Buy	中西麻美子 Mamiko Nakanishi	activist	300	¥2,343	+8.4%	¥703K ($5K)
2025-03-10	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	917.0K	¥2,615	-2.9%	¥198M ($1.3M)
2025-03-07	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	917.0K	¥2,614	+2.8%	¥198M ($1.3M)
2025-03-07	SELL	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	992.7K	¥2,614	+2.8%	¥1.4B ($9.0M)
2025-03-07	BUY	unknown	レック株式会社 LEC,INC.	strategic	575.1K	¥2,614	-2.8%	¥1.5B ($9.7M)
2025-03-07	BUY	unknown	レック株式会社 LEC,INC.	strategic	575.1K	¥2,614	-2.8%	¥1.5B ($9.7M)
2024-03-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	unknown	0	¥2,119	-19.9%	¥106M ($681K)
2024-03-07	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	161.7K	¥2,119	+19.9%	¥336M ($2.2M)
2023-11-29	BUY	unknown	中西昭夫 NAKANISHI AKIO	activist	299.0K	¥1,796	+41.4%	¥530M ($3.4M)
2023-11-29	BUY	unknown	中西満里子 Mariko Nakanishi	other	35.6K	¥1,796	+41.4%	¥64M ($413K)
2023-11-29	BUY	unknown	中西満里子 Mariko Nakanishi	other	35.6K	¥1,796	+41.4%	¥64M ($413K)
2023-11-29	BUY	unknown	中西昭夫 NAKANISHI AKIO	activist	299.0K	¥1,796	+41.4%	¥530M ($3.4M)
2023-02-07	SELL	unknown	エフエムアールエルエルシー(FMR LLC) FMR LLC	other	141.6K	¥1,952	-30.1%	¥534M ($3.4M)
2023-01-24	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.5M	¥1,775	+43.1%	¥466M ($3.0M)
2022-10-18	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.3M	¥1,844	+37.7%	¥116M ($750K)
2022-09-16	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.2M	¥1,795	+41.5%	¥115M ($745K)
2022-06-22	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.1M	¥1,332	+90.7%	¥84M ($542K)
2022-04-11	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.1M	¥1,219	+108.4%	¥77M ($496K)
2022-02-04	BUY	Market Buy	中西製作所取引先持株会理事長福島裕 Nakanishi Business Partner Stock Purchase Plan President Fukushima Yutaka	strategic	509.1K	¥1,278	+98.8%	¥81M ($525K)
2021-10-18	BUY	unknown	中西昭夫 NAKANISHI AKIO	strategic	362.3K	¥1,155	+119.9%	¥414M ($2.7M)
2021-10-18	BUY	unknown	中西昭夫 NAKANISHI AKIO	strategic	362.3K	¥1,155	+119.9%	¥414M ($2.7M)
2021-10-18	BUY	Market Buy	中西一真 NAKANISHI KAZUMA	activist	549.7K	¥1,155	+119.9%	¥83M ($536K)
2021-10-18	BUY	unknown	中西満里子 Mariko Nakanishi	unknown	35.6K	¥1,155	+119.9%	¥41M ($265K)
2021-09-22	BUY	Market Buy	シンプレクス・アセット・マネジメント株式会社 Simplex Asset Management Co., Ltd.	passive	1.0M	¥1,148	+121.3%	¥75M ($481K)
2021-08-10	BUY	Market Buy	G10キャピタル・リミテッド(G10 Capital Limited) G10 Capital Limited	passive	400.0K	¥1,157	+119.5%	¥463M ($3.0M)
2021-08-10	BUY	Market Buy	G10キャピタル・リミテッド(G10 Capital Limited) G10 Capital Limited	passive	400.0K	¥1,157	+119.5%	¥463M ($3.0M)

Frequently asked questions

Who has been buying Nakanishi Mfg. Co., Ltd. stock?: 11 distinct investors have filed 15 disclosed large-shareholding filings in Nakanishi Mfg. Co., Ltd. (5941), most recently on 2026-03-24. 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 Nakanishi Mfg. Co., Ltd. have?: Nakanishi Mfg. Co., Ltd. has 15 buy-side and 7 sell-side disclosures on record, covering ¥4.5B ($29.1M) in total reported value, spanning 2021-08-10 to 2026-03-24.
Where does StockDrifts get Nakanishi Mfg. 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 Nakanishi Mfg. Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.