Who has been buying Rion Co., Ltd. stock?

9 distinct investors have filed 14 disclosed large-shareholding filings in Rion Co., Ltd. (6823), 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 Rion Co., Ltd. have?

Rion Co., Ltd. has 14 buy-side and 13 sell-side disclosures on record, covering ¥4.1B ($26.5M) in total reported value, spanning 2021-12-22 to 2026-05-12.

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.

Rion Co., Ltd. 6823

Company

リオン株式会社Rion Co., Ltd.

Investors

Buys

Total Value

¥4.1B ($26.5M)

Avg Return

+24.29%

Last Filing

2026-05-12

Rion Co., Ltd. (6823) has 14 disclosed large-shareholding filings and 13 disclosed disposals on record, filed by 9 distinct investors. Together those filings cover ¥4.1B ($26.5M) in reported transaction value. The earliest filing StockDrifts holds for Rion Co., Ltd. is dated 2021-12-22; the most recent is 2026-05-12. Across these filings the average return since disclosure is +24.29%, 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
2026-07-23	SELL	unknown	アセットマネジメントOne株式会社	other	263.0K	¥3,380	+3.5%	¥772M ($5.0M)
2026-07-23	BUY	unknown	株式会社みずほ銀行	strategic	210.0K	¥3,380	-	-
2026-05-12	SELL	Market Buy	三井住友DSアセットマネジメント株式会社	passive	415.2K	¥3,550	+8.2%	¥245M ($1.6M)
2026-05-12	SELL	unknown	株式会社三井住友銀行	other	75.0K	¥3,550	+8.2%	¥272M ($1.8M)
2026-05-12	BUY	unknown	株式会社みずほ銀行	strategic	210.0K	¥3,550	-	-
2026-05-12	SELL	unknown	アセットマネジメントOne株式会社	other	491.6K	¥3,550	+8.2%	¥465M ($3.0M)
2025-10-07	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	483.6K	¥2,620	+24.4%	¥1.3B ($8.2M)
2025-10-07	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	152.2K	¥2,620	+24.4%	¥399M ($2.6M)
2025-07-07	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	210.0K	¥2,554	-	-
2025-07-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	622.0K	¥2,554	-27.6%	¥318M ($2.1M)
2025-07-07	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	2.9K	¥2,554	+27.6%	¥589M ($3.8M)
2024-11-08	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	408.3K	¥2,444	-33.4%	¥127M ($817K)
2024-11-08	SELL	Market Buy	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	13.1K	¥2,444	-33.4%	¥6M ($39K)
2024-11-08	SELL	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	75.0K	¥2,444	-33.4%	¥184M ($1.2M)
2024-06-21	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	210.0K	¥2,771	-	-
2024-06-21	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	745.4K	¥2,771	+17.6%	¥355M ($2.3M)
2024-06-21	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	16.5K	¥2,771	-	-
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	459.7K	¥2,930	+11.3%	¥1.3B ($8.7M)
2024-06-07	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	150.0K	¥2,930	+11.3%	¥440M ($2.8M)
2024-06-07	BUY	Market Buy	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	16.4K	¥2,930	+11.3%	¥48M ($310K)
2024-02-22	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	210.0K	¥2,831	-	-
2024-02-22	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	617.8K	¥2,831	+15.2%	¥492M ($3.2M)
2024-02-22	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	16.5K	¥2,831	-	-
2024-02-07	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	16.5K	¥2,543	+28.2%	¥42M ($271K)
2024-02-07	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	210.0K	¥2,543	+28.2%	¥534M ($3.4M)
2024-02-07	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	444.2K	¥2,543	+28.2%	¥1.1B ($7.3M)
2023-01-19	SELL	negotiated	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	281.2K	¥1,791	-82.0%	¥165M ($1.1M)
2023-01-19	BUY	negotiated	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	114.2K	¥1,791	-	-
2023-01-19	SELL	negotiated	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	strategic	100.0K	¥1,791	-82.0%	¥62M ($399K)
2022-11-07	SELL	negotiated	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	strategic	134.7K	¥1,874	-74.0%	¥122M ($789K)
2022-11-07	SELL	negotiated	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	372.7K	¥1,874	-74.0%	¥88M ($566K)
2022-11-07	SELL	negotiated	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	114.3K	¥1,874	-74.0%	¥28M ($179K)
2022-03-04	SELL	negotiated	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	strategic	200.0K	¥2,125	-53.4%	¥3M ($17K)
2022-03-04	BUY	negotiated	三井住友トラスト・アセットマネジメント株式会社 Sumitomo Mitsui Trust Asset Management Co.,Ltd.	other	419.3K	¥2,125	+53.4%	¥243M ($1.6M)
2022-03-04	BUY	negotiated	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	129.3K	¥2,125	+53.4%	¥21M ($135K)
2021-12-22	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	348.2K	¥2,313	+40.9%	¥794M ($5.1M)
2021-12-22	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	150.0K	¥2,313	-	-

Frequently asked questions

Who has been buying Rion Co., Ltd. stock?: 9 distinct investors have filed 14 disclosed large-shareholding filings in Rion Co., Ltd. (6823), 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 Rion Co., Ltd. have?: Rion Co., Ltd. has 14 buy-side and 13 sell-side disclosures on record, covering ¥4.1B ($26.5M) in total reported value, spanning 2021-12-22 to 2026-05-12.
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.