Who has been buying OYO Corporation stock?

7 distinct investors have filed 14 disclosed large-shareholding filings in OYO Corporation (9755), most recently on 2026-04-23. 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 OYO Corporation have?

OYO Corporation has 14 buy-side and 12 sell-side disclosures on record, covering ¥4.0B ($25.9M) in total reported value, spanning 2021-07-07 to 2026-04-23.

Where does StockDrifts get OYO Corporation 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.

OYO Corporation 9755

Company

応用地質株式会社OYO Corporation

Investors

Buys

Total Value

¥4.0B ($25.9M)

Avg Return

+52.86%

Last Filing

2026-04-23

OYO Corporation (9755) has 14 disclosed large-shareholding filings and 12 disclosed disposals on record, filed by 7 distinct investors. Together those filings cover ¥4.0B ($25.9M) in reported transaction value. The earliest filing StockDrifts holds for OYO Corporation is dated 2021-07-07; the most recent is 2026-04-23. 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 +52.86%, 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
2026-04-23	SELL	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	2.8M	¥2,759	-3.1%	¥698M ($4.5M)
2025-10-17	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	3.1M	¥2,885	-1.8%	¥581M ($3.7M)
2024-05-09	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	300.0K	¥2,377	+19.2%	¥713M ($4.6M)
2024-05-09	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	370.7K	¥2,377	-19.2%	¥140M ($905K)
2024-05-09	SELL	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	392.8K	¥2,377	-19.2%	¥348M ($2.2M)
2024-05-09	SELL	unknown	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	13.6K	¥2,377	-19.2%	¥311M ($2.0M)
2023-06-12	SELL	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	3.0M	¥1,894	-49.6%	¥486M ($3.1M)
2023-05-19	BUY	unknown	須賀るり子 Ruriko Suga	strategic	1.5M	¥1,957	+44.8%	¥2.9B ($18.6M)
2023-05-19	BUY	unknown	有限会社エーケー AK Corp.	strategic	320.8K	¥1,957	+44.8%	¥628M ($4.0M)
2023-02-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	428.3K	¥1,963	-44.3%	¥25M ($163K)
2023-02-07	BUY	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	539.5K	¥1,963	+44.3%	¥1.1B ($6.8M)
2023-02-07	SELL	unknown	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	143.3K	¥1,963	-44.3%	¥252M ($1.6M)
2023-02-07	SELL	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	300.0K	¥1,963	-44.3%	¥257M ($1.7M)
2023-01-11	SELL	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	442.0K	¥2,157	-31.3%	¥50M ($321K)
2023-01-11	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	3.3M	¥2,157	+31.3%	¥686M ($4.4M)
2023-01-11	BUY	Market Buy	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	271.4K	¥2,157	+31.3%	¥585M ($3.8M)
2023-01-11	BUY	Market Buy	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	430.0K	¥2,157	+31.3%	¥39M ($250K)
2023-01-11	BUY	Market Buy	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	539.5K	¥2,157	+31.3%	¥33M ($214K)
2021-12-28	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	3.1M	¥2,118	+33.8%	¥582M ($3.8M)
2021-12-07	SELL	unknown	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	544.9K	¥2,019	-40.3%	¥11M ($69K)
2021-12-07	BUY	unknown	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	3.2K	¥2,019	+40.3%	¥237M ($1.5M)
2021-12-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	483.5K	¥2,019	-40.3%	¥70M ($452K)
2021-12-07	BUY	unknown	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	430.0K	¥2,019	+40.3%	¥868M ($5.6M)
2021-12-07	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	activist	2.8M	¥2,019	+40.3%	¥1.3B ($8.6M)
2021-11-22	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	passive	2.1M	¥1,982	+42.9%	¥1.2B ($7.8M)
2021-11-08	BUY	Market Buy	シンフォニー・フィナンシャル・パートナーズ(シンガポール)ピーティーイー・リミテッド (Symphony Financial Partners (Singapore) Pte. Ltd.) Symphony Financial Partners (Singapore) Pte. Ltd.	passive	1.5M	¥1,821	+55.6%	¥2.8B ($18.0M)
2021-07-07	SELL	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	518.5K	¥1,317	-115.1%	¥14M ($91K)
2021-07-07	BUY	Market Buy	みずほ信託銀行株式会社 Mizuho Trust & Banking Co., Ltd.	other	548.6K	¥1,317	+115.1%	¥277M ($1.8M)
2021-07-07	BUY	Market Buy	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	150.1K	¥1,317	+115.1%	¥116M ($748K)
2021-07-07	BUY	Market Buy	株式会社みずほ銀行 Mizuho Bank, Ltd.	strategic	430.0K	¥1,317	+115.1%	¥18M ($113K)

Frequently asked questions

Who has been buying OYO Corporation stock?: 7 distinct investors have filed 14 disclosed large-shareholding filings in OYO Corporation (9755), most recently on 2026-04-23. 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 OYO Corporation have?: OYO Corporation has 14 buy-side and 12 sell-side disclosures on record, covering ¥4.0B ($25.9M) in total reported value, spanning 2021-07-07 to 2026-04-23.
Where does StockDrifts get OYO Corporation 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 OYO Corporation. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.