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

6 distinct investors have filed 11 disclosed large-shareholding filings in Onamba Co., Ltd. (5816), most recently on 2026-02-02. 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 Onamba Co., Ltd. have?

Onamba Co., Ltd. has 11 buy-side and 6 sell-side disclosures on record, covering ¥1.2B ($7.9M) in total reported value, spanning 2021-08-16 to 2026-02-02.

Where does StockDrifts get Onamba 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.

Onamba Co., Ltd. 5816

Company

オーナンバ株式会社Onamba Co., Ltd.

Investors

Buys

Total Value

¥1.2B ($7.9M)

Avg Return

+117.20%

Last Filing

2026-02-02

Onamba Co., Ltd. (5816) has 11 disclosed large-shareholding filings and 6 disclosed disposals on record, filed by 6 distinct investors. Together those filings cover ¥1.2B ($7.9M) in reported transaction value. The earliest filing StockDrifts holds for Onamba Co., Ltd. is dated 2021-08-16; the most recent is 2026-02-02. 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 +117.20%, 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
2026-02-02	BUY	Market Buy	Be Brave株式会社代表取締役泉田和人 Be Brave Inc.	activist	1.3M	¥1,440	+35.5%	¥539M ($3.5M)
2025-11-12	BUY	Market Buy	Be Brave株式会社代表取締役泉田和人 Be Brave Inc.	activist	946.8K	¥1,466	+33.1%	¥195M ($1.3M)
2025-11-07	BUY	Market Buy	Be Brave株式会社代表取締役泉田和人 Be Brave Inc.	activist	814.4K	¥1,415	+37.9%	¥226M ($1.5M)
2025-11-04	BUY	Market Buy	Be Brave株式会社代表取締役泉田和人 Be Brave Inc.	activist	654.2K	¥1,370	+42.4%	¥896M ($5.8M)
2024-06-21	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥1,282	+52.2%	¥501M ($3.2M)
2024-06-21	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	118.1K	¥1,282	-52.2%	¥259M ($1.7M)
2024-05-22	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥1,248	+56.3%	¥488M ($3.1M)
2024-05-22	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	320.6K	¥1,248	-56.3%	¥179M ($1.2M)
2024-03-25	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥1,325	+47.3%	¥518M ($3.3M)
2024-03-25	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	462.9K	¥1,325	-47.3%	¥175M ($1.1M)
2023-08-22	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥874	+123.2%	¥342M ($2.2M)
2023-08-22	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	595.4K	¥874	+123.2%	¥183M ($1.2M)
2023-07-24	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥1,023	+90.7%	¥400M ($2.6M)
2023-07-24	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	386.0K	¥1,023	+90.7%	¥150M ($970K)
2023-01-30	SELL	negotiated	三菱UFJモルガン・スタンレー証券株式会社 Mitsubishi UFJ Morgan Stanley Securities Co., Ltd.	unknown	0	¥757	-157.7%	¥125M ($803K)
2023-01-30	BUY	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	517.7K	¥757	+157.7%	¥392M ($2.5M)
2023-01-30	BUY	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	strategic	46.0K	¥757	+157.7%	¥35M ($225K)
2023-01-16	BUY	negotiated	三菱UFJモルガン・スタンレー証券株式会社 Mitsubishi UFJ Morgan Stanley Securities Co., Ltd.	other	164.2K	¥765	+155.0%	¥126M ($810K)
2023-01-16	BUY	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	strategic	46.0K	¥765	+155.0%	¥35M ($227K)
2023-01-16	BUY	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	517.7K	¥765	+155.0%	¥396M ($2.6M)
2021-11-08	BUY	Market Buy	株式会社三井住友銀行 Sumitomo Mitsui Banking Corporation	other	391.0K	¥590	+230.7%	¥231M ($1.5M)
2021-11-08	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	238.8K	¥590	+230.7%	¥141M ($909K)
2021-08-16	SELL	negotiated	三菱UFJモルガン・スタンレー証券株式会社 Mitsubishi UFJ Morgan Stanley Securities Co., Ltd.	unknown	0	¥734	-165.8%	¥37M ($238K)
2021-08-16	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	strategic	46.0K	¥734	-165.8%	¥29M ($184K)
2021-08-16	BUY	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	517.7K	¥734	+165.8%	¥380M ($2.5M)

Frequently asked questions

Who has been buying Onamba Co., Ltd. stock?: 6 distinct investors have filed 11 disclosed large-shareholding filings in Onamba Co., Ltd. (5816), most recently on 2026-02-02. 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 Onamba Co., Ltd. have?: Onamba Co., Ltd. has 11 buy-side and 6 sell-side disclosures on record, covering ¥1.2B ($7.9M) in total reported value, spanning 2021-08-16 to 2026-02-02.
Where does StockDrifts get Onamba 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 Onamba Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.