Who has been buying Adtec Plasma Technology Co., Ltd. stock?

7 distinct investors have filed 11 disclosed large-shareholding filings in Adtec Plasma Technology Co., Ltd. (6668), most recently on 2026-05-12. 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 Adtec Plasma Technology Co., Ltd. have?

Adtec Plasma Technology Co., Ltd. has 11 buy-side and 16 sell-side disclosures on record, covering ¥2.8B ($17.9M) in total reported value, spanning 2021-03-22 to 2026-05-12.

Where does StockDrifts get Adtec Plasma Technology 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.

Adtec Plasma Technology Co., Ltd. 6668

Company

株式会社アドテックプラズマテクノロジーAdtec Plasma Technology Co., Ltd.

Investors

Buys

Total Value

¥2.8B ($17.9M)

Avg Return

+67.08%

Last Filing

2026-05-12

Adtec Plasma Technology Co., Ltd. (6668) has 11 disclosed large-shareholding filings and 16 disclosed disposals on record, filed by 7 distinct investors. Together those filings cover ¥2.8B ($17.9M) in reported transaction value. The earliest filing StockDrifts holds for Adtec Plasma Technology Co., Ltd. is dated 2021-03-22; the most recent is 2026-05-12. 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 +67.08%, 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
2026-07-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	346.3K	¥3,330	-15.8%	¥383M ($2.5M)
2026-05-12	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	461.4K	¥3,215	-0.2%	¥635M ($4.1M)
2026-03-06	SELL	Market Buy	株式会社SBI証券	other	52.5K	¥1,877	-44.2%	¥142M ($916K)
2026-03-06	BUY	Market Buy	SBIアセットマネジメント株式会社	passive	391.7K	¥1,877	-44.2%	¥1.1B ($6.8M)
2026-02-20	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	658.9K	¥1,910	+41.7%	¥380M ($2.5M)
2026-02-06	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	459.6K	¥1,880	+43.9%	¥864M ($5.6M)
2025-11-10	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	94.7K	¥1,240	+118.2%	¥117M ($758K)
2025-11-10	BUY	Market Buy	SBIアセットマネジメント株式会社 SBI Asset Management Co., Ltd.	passive	391.7K	¥1,240	+118.2%	¥486M ($3.1M)
2025-05-22	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	323.4K	¥1,165	-132.3%	¥216M ($1.4M)
2025-05-09	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	509.3K	¥1,170	-131.3%	¥231M ($1.5M)
2025-02-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	706.2K	¥1,411	-91.8%	¥197M ($1.3M)
2025-02-03	SELL	unknown	藤井修逸 Shuitsu Fujii	strategic	1.9M	¥1,405	-92.6%	¥421M ($2.7M)
2024-11-08	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	846.4K	¥1,295	+109.0%	¥118M ($760K)
2024-09-06	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	755.5K	¥1,773	+52.6%	¥181M ($1.2M)
2024-08-22	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	653.8K	¥1,907	+41.9%	¥198M ($1.3M)
2024-08-07	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	549.9K	¥1,722	+57.1%	¥160M ($1.0M)
2024-01-11	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	456.7K	¥1,783	+51.8%	¥814M ($5.3M)
2023-12-07	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.2M	¥1,551	-74.5%	¥206M ($1.3M)
2022-09-20	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.4M	¥1,579	-71.4%	¥141M ($910K)
2022-09-20	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.4M	¥1,579	+71.4%	¥141M ($910K)
2022-09-20	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.4M	¥1,579	+71.4%	¥141M ($910K)
2022-09-07	SELL	Market Buy	ベイビュー・アセット・マネジメント株式会社 Bayview Asset Management Co., Ltd.	passive	380.6K	¥1,587	-70.5%	¥166M ($1.1M)
2022-09-01	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.5M	¥1,688	+60.3%	¥155M ($1.0M)
2022-09-01	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.5M	¥1,688	-60.3%	¥155M ($1.0M)
2022-09-01	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.5M	¥1,688	+60.3%	¥155M ($1.0M)
2022-08-22	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.6M	¥1,764	+53.4%	¥161M ($1.0M)
2022-08-22	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.6M	¥1,764	+53.4%	¥161M ($1.0M)
2022-08-22	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.6M	¥1,764	-53.4%	¥161M ($1.0M)
2022-08-08	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,861	-45.4%	¥161M ($1.0M)
2022-08-08	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,861	+45.4%	¥161M ($1.0M)
2022-08-08	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,861	+45.4%	¥161M ($1.0M)
2022-07-29	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,854	-46.0%	¥161M ($1.0M)
2022-07-29	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,854	+46.0%	¥161M ($1.0M)
2022-07-29	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.7M	¥1,854	+46.0%	¥161M ($1.0M)
2022-07-21	SELL	unknown	藤井修逸 Shuitsu Fujii	other	2.8M	¥1,890	-43.2%	¥172M ($1.1M)
2022-07-21	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.8M	¥1,890	+43.2%	¥172M ($1.1M)
2022-07-21	BUY	unknown	藤井修逸 Shuitsu Fujii	other	2.8M	¥1,890	+43.2%	¥172M ($1.1M)
2022-01-21	BUY	Market Buy	ベイビュー・アセット・マネジメント株式会社 Bayview Asset Management Co., Ltd.	passive	485.0K	¥2,527	+7.1%	¥1.2B ($7.9M)
2021-07-06	SELL	Market Buy	三井住友DSアセットマネジメント株式会社 Sumitomo Mitsui DS Asset Management Company, Limited	passive	408.4K	¥1,782	-51.9%	¥173M ($1.1M)
2021-03-22	BUY	unknown	三井住友DSアセットマネジメント株式会社 Sumitomo Mitsui DS Asset Management Company, Limited	passive	505.8K	¥1,378	+96.4%	¥690M ($4.4M)
2021-03-22	SELL	unknown	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	200	¥1,378	-96.4%	¥130M ($840K)

Frequently asked questions

Who has been buying Adtec Plasma Technology Co., Ltd. stock?: 7 distinct investors have filed 11 disclosed large-shareholding filings in Adtec Plasma Technology Co., Ltd. (6668), most recently on 2026-05-12. 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 Adtec Plasma Technology Co., Ltd. have?: Adtec Plasma Technology Co., Ltd. has 11 buy-side and 16 sell-side disclosures on record, covering ¥2.8B ($17.9M) in total reported value, spanning 2021-03-22 to 2026-05-12.
Where does StockDrifts get Adtec Plasma Technology 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 Adtec Plasma Technology Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.