Who has been buying Otsuka Holdings Co., Ltd. stock?

15 distinct investors have filed 26 disclosed large-shareholding filings in Otsuka Holdings Co., Ltd. (4578), most recently on 2026-03-05. 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 Otsuka Holdings Co., Ltd. have?

Otsuka Holdings Co., Ltd. has 26 buy-side and 6 sell-side disclosures on record, covering ¥368.7B ($2.4B) in total reported value, spanning 2022-03-23 to 2026-03-05.

Where does StockDrifts get Otsuka Holdings 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.

Otsuka Holdings Co., Ltd. 4578

Company

大塚ホールディングス株式会社Otsuka Holdings Co., Ltd.

Investors

Buys

Total Value

¥368.7B ($2.4B)

Avg Return

+87.20%

Last Filing

2026-03-05

Otsuka Holdings Co., Ltd. (4578) has 26 disclosed large-shareholding filings and 6 disclosed disposals on record, filed by 15 distinct investors. Together those filings cover ¥368.7B ($2.4B) in reported transaction value. The earliest filing StockDrifts holds for Otsuka Holdings Co., Ltd. is dated 2022-03-23; the most recent is 2026-03-05. 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 +87.20%, 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
2026-03-05	BUY	unknown	野村アセットマネジメント株式会社	other	26.4M	¥10,170	+5.1%	¥281.9B ($1.8B)
2026-03-05	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	-40.8K	¥10,170	+5.1%	¥436M ($2.8M)
2026-03-05	BUY	unknown	野村證券株式会社	other	967.5K	¥10,170	+5.1%	¥10.3B ($66.7M)
2025-12-02	BUY	unknown	野村アセットマネジメント株式会社	other	26.2M	¥8,915	+19.9%	¥279.7B ($1.8B)
2025-12-02	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	260.7K	¥8,915	-19.9%	¥2.8B ($18.0M)
2025-12-02	BUY	unknown	野村證券株式会社	other	491.6K	¥8,915	+19.9%	¥5.3B ($33.9M)
2025-10-07	BUY	Market Buy	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	25.7M	¥8,440	+26.6%	¥917M ($5.9M)
2025-10-07	BUY	Market Buy	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	2.3M	¥8,440	+26.6%	¥7.8B ($50.3M)
2025-10-07	BUY	Market Buy	野村證券株式会社 Nomura Securities Co.,Ltd.	other	387.6K	¥8,440	+26.6%	¥45.8B ($295.7M)
2025-09-19	SELL	unknown	アモーヴァ・アセットマネジメント株式会社 Amova Asset Management Co., Ltd.	other	12.3M	¥8,141	-31.3%	¥6.2B ($39.9M)
2025-09-19	SELL	unknown	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	12.5M	¥8,141	-31.3%	¥14.6B ($94.1M)
2025-06-19	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	13.0M	¥7,011	+52.4%	¥91.4B ($589.6M)
2025-06-19	BUY	unknown	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	14.3M	¥7,011	+52.4%	¥100.3B ($647.1M)
2024-09-20	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	26.3M	¥7,922	+34.9%	¥208.2B ($1.3B)
2024-09-20	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	1.4M	¥7,922	+34.9%	¥11.2B ($72.4M)
2024-09-20	BUY	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	323.3K	¥7,922	+34.9%	¥2.6B ($16.5M)
2023-04-05	BUY	Market Buy	ブラックロック・インスティテューショナル・トラスト・カンパニー、エヌ.エイ.(BlackRock Institutional Trust Company BlackRock Institutional Trust Company, N.A.	passive	7.7M	¥4,224	+153.0%	¥5.4B ($35.0M)
2023-04-05	SELL	Market Buy	ブラックロック・インベストメント・マネジメント(ユーケー)リミテッドLimited) BlackRock Investment Management (UK	passive	648.1K	¥4,224	-153.0%	¥471M ($3.0M)
2023-04-05	BUY	Market Buy	ブラックロック・ファンド・アドバイザーズ BlackRock Fund Advisors	passive	9.7M	¥4,224	+153.0%	¥7.3B ($47.1M)
2023-04-05	BUY	Market Buy	ブラックロック・アセット・マネジメント・アイルランド・リミテッド BlackRock Asset Management Ireland Limited	passive	2.4M	¥4,224	+153.0%	¥707M ($4.6M)
2023-04-05	BUY	Market Buy	ブラックロック・アセット・マネジメント・カナダ・リミテッド BlackRock Asset Management Canada Limited	passive	662.2K	¥4,224	+153.0%	¥2.8B ($18.0M)
2023-04-05	SELL	Market Buy	ブラックロック・ファンド・マネジャーズ・リミテッド BlackRock Fund Managers Limited	passive	864.0K	¥4,224	-153.0%	¥236M ($1.5M)
2023-04-05	BUY	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	1.6M	¥4,224	+153.0%	¥2.4B ($15.2M)
2023-04-05	BUY	Market Buy	アペリオ・グループ・エルエルシー(Aperio Group Aperio Group, LLC	passive	690.3K	¥4,224	+153.0%	¥2.9B ($18.8M)
2023-04-05	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	9.7M	¥4,224	+153.0%	¥6.8B ($44.1M)
2022-06-06	BUY	Market Buy	ブラックロック・インベストメント・マネジメント(ユーケー)リミテッドLimited) BlackRock Investment Management (UK	passive	757.8K	¥4,365	+144.8%	¥3.3B ($21.3M)
2022-06-06	BUY	Market Buy	ブラックロック・インスティテューショナル・トラスト・カンパニー、エヌ.エイ.(BlackRock Institutional Trust Company BlackRock Institutional Trust Company, N.A.	passive	6.4M	¥4,365	+144.8%	¥28.1B ($181.3M)
2022-06-06	BUY	Market Buy	ブラックロック・ファンド・アドバイザーズ BlackRock Fund Advisors	passive	7.9M	¥4,365	+144.8%	¥34.7B ($223.8M)
2022-06-06	BUY	Market Buy	ブラックロック・アセット・マネジメント・アイルランド・リミテッド BlackRock Asset Management Ireland Limited	passive	2.3M	¥4,365	+144.8%	¥10.1B ($65.0M)
2022-06-06	BUY	Market Buy	ブラックロック・ファンド・マネジャーズ・リミテッド BlackRock Fund Managers Limited	passive	877.9K	¥4,365	+144.8%	¥3.8B ($24.7M)
2022-06-06	BUY	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	989.0K	¥4,365	+144.8%	¥4.3B ($27.9M)
2022-06-06	BUY	Market Buy	アペリオ・グループ・エルエルシー(Aperio Group Aperio Group, LLC	passive	680.3K	¥4,365	+144.8%	¥3.0B ($19.2M)
2022-06-06	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	8.1M	¥4,365	+144.8%	¥35.4B ($228.5M)
2022-03-23	SELL	unknown	大塚一郎 Ichiro Otsuka	strategic	57.7M	¥4,270	-150.2%	¥27.2B ($175.2M)

Frequently asked questions

Who has been buying Otsuka Holdings Co., Ltd. stock?: 15 distinct investors have filed 26 disclosed large-shareholding filings in Otsuka Holdings Co., Ltd. (4578), most recently on 2026-03-05. 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 Otsuka Holdings Co., Ltd. have?: Otsuka Holdings Co., Ltd. has 26 buy-side and 6 sell-side disclosures on record, covering ¥368.7B ($2.4B) in total reported value, spanning 2022-03-23 to 2026-03-05.
Where does StockDrifts get Otsuka Holdings 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 Otsuka Holdings Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.