Who has been buying Seiko Electric Co., Ltd. stock?

10 distinct investors have filed 18 disclosed large-shareholding filings in Seiko Electric Co., Ltd. (6653), most recently on 2026-04-03. 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 Seiko Electric Co., Ltd. have?

Seiko Electric Co., Ltd. has 18 buy-side and 34 sell-side disclosures on record, covering ¥1.6B ($10.1M) in total reported value, spanning 2021-04-07 to 2026-04-03.

Where does StockDrifts get Seiko Electric 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.

Seiko Electric Co., Ltd. 6653

Company

株式会社正興電機製作所Seiko Electric Co., Ltd.

Investors

Buys

Total Value

¥1.6B ($10.1M)

Avg Return

+124.08%

Last Filing

2026-04-03

Seiko Electric Co., Ltd. (6653) has 18 disclosed large-shareholding filings and 34 disclosed disposals on record, filed by 10 distinct investors. Together those filings cover ¥1.6B ($10.1M) in reported transaction value. The earliest filing StockDrifts holds for Seiko Electric Co., Ltd. is dated 2021-04-07; the most recent is 2026-04-03. 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 +124.08%, 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
2026-04-03	BUY	unknown	株式会社クラフティア KRAFTIA CORPORATION	other	846.3K	¥2,228	+11.1%	¥1.9B ($12.2M)
2026-04-03	BUY	unknown	株式会社クラフティア KRAFTIA CORPORATION	other	846.3K	¥2,228	+11.1%	¥1.9B ($12.2M)
2026-03-31	SELL	unknown	株式会社クラフティア KRAFTIA CORPORATION	other	846.3K	¥2,127	-18.1%	¥340M ($2.2M)
2026-03-31	SELL	unknown	株式会社クラフティア KRAFTIA CORPORATION	other	1.0M	¥2,127	-18.1%	¥639M ($4.1M)
2025-08-06	SELL	negotiated	株式会社日立製作所 Hitachi, Ltd.	strategic	555.3K	¥1,559	-80.2%	¥219M ($1.4M)
2025-05-30	SELL	unknown	西日本鉄道株式会社 Nishi-Nippon Railroad Co.,Ltd.	other	933.0K	¥1,334	-110.6%	¥128M ($826K)
2024-11-20	SELL	negotiated	株式会社日立製作所 Hitachi, Ltd.	strategic	630.3K	¥1,199	-134.3%	¥100M ($643K)
2024-11-19	SELL	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	500.1K	¥1,196	-134.9%	¥20M ($126K)
2024-11-19	SELL	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	686.4K	¥1,196	-134.9%	¥26M ($165K)
2024-06-13	SELL	negotiated	株式会社日立製作所 Hitachi, Ltd.	strategic	713.6K	¥1,556	-80.5%	¥198M ($1.3M)
2023-12-22	SELL	unknown	西日本鉄道株式会社 Nishi-Nippon Railroad Co.,Ltd.	other	933.0K	¥1,120	-150.8%	¥58M ($373K)
2023-12-22	BUY	unknown	西日本鉄道株式会社 Nishi-Nippon Railroad Co.,Ltd.	other	933.0K	¥1,120	+150.8%	¥1.0B ($6.7M)
2022-11-08	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	209.5K	¥991	+183.4%	¥42M ($274K)
2022-11-08	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	130.0K	¥991	+183.4%	¥12M ($81K)
2022-11-08	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	217.2K	¥991	-183.4%	¥131M ($846K)
2022-08-04	SELL	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	516.4K	¥1,097	-156.1%	¥59M ($384K)
2022-08-04	SELL	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	708.8K	¥1,097	-156.1%	¥83M ($535K)
2022-07-22	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	165.8K	¥1,214	+131.4%	¥201M ($1.3M)
2022-07-22	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	117.7K	¥1,214	+131.4%	¥143M ($922K)
2022-07-22	BUY	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	348.7K	¥1,214	+131.4%	¥423M ($2.7M)
2022-07-07	SELL	Market Buy	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	166.9K	¥1,053	-166.8%	¥12M ($77K)
2022-07-07	SELL	Market Buy	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	-2.3K	¥1,053	-166.8%	¥169M ($1.1M)
2022-07-07	BUY	Market Buy	野村證券株式会社 Nomura Securities Co.,Ltd.	other	458.9K	¥1,053	+166.8%	¥134M ($865K)
2022-06-01	SELL	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	571.3K	¥1,135	-147.5%	¥60M ($388K)
2022-06-01	SELL	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	784.0K	¥1,135	-147.5%	¥83M ($535K)
2022-04-07	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	177.9K	¥1,208	+132.5%	¥2M ($10K)
2022-04-07	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	157.7K	¥1,208	-132.5%	¥114M ($737K)
2022-04-07	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	331.8K	¥1,208	-132.5%	¥187M ($1.2M)
2022-04-05	SELL	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	624.4K	¥1,266	-121.9%	¥69M ($443K)
2022-04-05	SELL	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	857.0K	¥1,266	-121.9%	¥94M ($607K)
2022-03-23	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	176.8K	¥1,262	+122.6%	¥223M ($1.4M)
2022-03-23	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	3.0K	¥1,262	+122.6%	¥4M ($24K)
2022-03-23	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	486.5K	¥1,262	-122.6%	¥16M ($103K)
2022-02-22	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	131.9K	¥1,049	+167.8%	¥4M ($26K)
2022-02-22	BUY	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	394.7K	¥1,049	+167.8%	¥408M ($2.6M)
2022-02-08	SELL	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	678.2K	¥1,022	-174.8%	¥55M ($357K)
2022-02-08	SELL	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	930.9K	¥1,022	-174.8%	¥75M ($482K)
2022-01-11	SELL	Market Buy	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	177.0K	¥1,139	-146.6%	¥17M ($111K)
2022-01-11	SELL	Market Buy	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	2.2K	¥1,139	-146.6%	¥142M ($917K)
2022-01-11	BUY	Market Buy	野村證券株式会社 Nomura Securities Co.,Ltd.	other	499.1K	¥1,139	+146.6%	¥428M ($2.8M)
2021-12-22	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	128.3K	¥1,163	+141.5%	¥149M ($963K)
2021-12-22	BUY	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	527.8K	¥1,163	+141.5%	¥614M ($4.0M)
2021-12-10	BUY	unknown	九州電力送配電株式会社 Kyushu Electric Power Transmission and Distribution Co., Ltd.	other	731.9K	¥1,215	+131.2%	¥889M ($5.7M)
2021-12-10	BUY	unknown	九州電力株式会社 Kyushu Electric Power Company, Incorporated	other	1.0M	¥1,215	+131.2%	¥1.2B ($7.9M)
2021-11-22	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	191.0K	¥1,253	+124.2%	¥17M ($112K)
2021-11-22	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	377.5K	¥1,253	-124.2%	¥8M ($51K)
2021-11-22	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	123.0K	¥1,253	-124.2%	¥73M ($469K)
2021-09-24	SELL	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	177.6K	¥1,460	-92.4%	¥18M ($119K)
2021-09-24	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	382.6K	¥1,460	+92.4%	¥559M ($3.6M)
2021-09-24	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	181.5K	¥1,460	-92.4%	¥550M ($3.5M)

Showing the 50 most recent of 60 filings.

Frequently asked questions

Who has been buying Seiko Electric Co., Ltd. stock?: 10 distinct investors have filed 18 disclosed large-shareholding filings in Seiko Electric Co., Ltd. (6653), most recently on 2026-04-03. 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 Seiko Electric Co., Ltd. have?: Seiko Electric Co., Ltd. has 18 buy-side and 34 sell-side disclosures on record, covering ¥1.6B ($10.1M) in total reported value, spanning 2021-04-07 to 2026-04-03.
Where does StockDrifts get Seiko Electric 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 Seiko Electric Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.