Who has been buying Riken Technos Corporation stock?

8 distinct investors have filed 4 disclosed large-shareholding filings in Riken Technos Corporation (4220), most recently on 2026-04-22. 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 Riken Technos Corporation have?

Riken Technos Corporation has 4 buy-side and 10 sell-side disclosures on record, covering ¥1.0B ($6.6M) in total reported value, spanning 2021-12-07 to 2026-04-22.

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.

Riken Technos Corporation 4220

Company

リケンテクノス株式会社Riken Technos Corporation

Investors

Buys

Total Value

¥1.0B ($6.6M)

Avg Return

+154.77%

Last Filing

2026-04-22

Riken Technos Corporation (4220) has 4 disclosed large-shareholding filings and 10 disclosed disposals on record, filed by 8 distinct investors. Together those filings cover ¥1.0B ($6.6M) in reported transaction value. The earliest filing StockDrifts holds for Riken Technos Corporation is dated 2021-12-07; the most recent is 2026-04-22. Across these filings the average return since disclosure is +154.77%, 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	BUY	Market Buy	みずほ信託銀行株式会社	strategic	1.7M	¥1,802	+34.6%	¥1.2B ($7.5M)
2026-07-07	BUY	unknown	株式会社みずほ銀行	strategic	1.9M	¥1,802	-	-
2026-07-07	BUY	unknown	アセットマネジメントOne株式会社	other	579.7K	¥1,802	-	-
2026-04-22	SELL	Market Buy	三井住友DSアセットマネジメント株式会社	passive	1.1M	¥1,671	-45.2%	¥857M ($5.5M)
2026-04-22	SELL	unknown	株式会社三井住友銀行	other	1.3M	¥1,671	-45.2%	¥317M ($2.0M)
2026-04-22	BUY	unknown	SMBC日興証券株式会社	other	68.1K	¥1,671	-	¥114M ($734K)
2024-08-21	SELL	negotiated	株式会社りそな銀行 Resona Bank, Limited.	strategic	1.9M	¥959	-153.0%	¥567M ($3.7M)
2024-08-21	BUY	negotiated	りそなアセットマネジメント株式会社 Resona Asset Management Co., Ltd.	other	657.6K	¥959	+153.0%	¥225M ($1.4M)
2024-06-07	SELL	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	1.6M	¥993	-144.3%	¥127M ($822K)
2024-06-07	BUY	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	1.8M	¥993	+144.3%	¥593M ($3.8M)
2023-11-22	SELL	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	2.3M	¥821	-195.5%	¥479M ($3.1M)
2023-11-22	SELL	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	strategic	1.3M	¥821	-195.5%	¥168M ($1.1M)
2023-11-22	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	723.3K	¥821	-195.5%	¥274M ($1.8M)
2022-12-22	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	1.4M	¥479	-406.5%	¥332M ($2.1M)
2022-12-22	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	2.0M	¥479	-	-
2022-09-07	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	2.0M	¥521	-365.6%	¥441M ($2.8M)
2022-09-07	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	2.0M	¥521	-	-
2021-12-07	BUY	Market Buy	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	2.9M	¥512	+373.8%	¥46M ($296K)
2021-12-07	BUY	Market Buy	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	strategic	1.5M	¥512	+373.8%	¥204M ($1.3M)
2021-12-07	SELL	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	1.1M	¥512	-373.8%	¥138M ($889K)

Frequently asked questions

Who has been buying Riken Technos Corporation stock?: 8 distinct investors have filed 4 disclosed large-shareholding filings in Riken Technos Corporation (4220), most recently on 2026-04-22. 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 Riken Technos Corporation have?: Riken Technos Corporation has 4 buy-side and 10 sell-side disclosures on record, covering ¥1.0B ($6.6M) in total reported value, spanning 2021-12-07 to 2026-04-22.
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.