Who has been buying Santen Pharmaceutical Co., Ltd. stock?

24 distinct investors have filed 46 disclosed large-shareholding filings in Santen Pharmaceutical Co., Ltd. (4536), most recently on 2025-10-08. 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 Santen Pharmaceutical Co., Ltd. have?

Santen Pharmaceutical Co., Ltd. has 46 buy-side and 29 sell-side disclosures on record, covering ¥333.5B ($2.2B) in total reported value, spanning 2021-10-20 to 2025-10-08.

Where does StockDrifts get Santen Pharmaceutical 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.

Santen Pharmaceutical Co., Ltd. 4536

Company

参天製薬株式会社Santen Pharmaceutical Co., Ltd.

Investors

Buys

Total Value

¥333.5B ($2.2B)

Avg Return

+34.62%

Last Filing

2025-10-08

Santen Pharmaceutical Co., Ltd. (4536) has 46 disclosed large-shareholding filings and 29 disclosed disposals on record, filed by 24 distinct investors. Together those filings cover ¥333.5B ($2.2B) in reported transaction value. The earliest filing StockDrifts holds for Santen Pharmaceutical Co., Ltd. is dated 2021-10-20; the most recent is 2025-10-08. 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 +34.62%, 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
2025-10-08	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	31.6M	¥1,578.5	+11.0%	¥5.5B ($35.5M)
2025-09-22	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	28.1M	¥1,646	+6.4%	¥6.1B ($39.2M)
2025-09-19	BUY	Market Buy	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	9.3M	¥1,650	+6.2%	¥3.0B ($19.7M)
2025-09-19	SELL	Market Buy	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	9.7M	¥1,650	-6.2%	¥1.1B ($7.3M)
2025-03-24	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	24.4M	¥1,441.5	+21.5%	¥148M ($954K)
2025-03-05	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	24.3M	¥1,434.5	+22.1%	¥5.0B ($32.3M)
2025-02-07	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	21.1M	¥1,445	+21.3%	¥5.3B ($34.3M)
2024-12-05	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	4.2M	¥1,788.5	-2.0%	¥7.5B ($48.6M)
2024-12-05	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	3.8M	¥1,788.5	-2.0%	¥6.8B ($44.0M)
2024-12-05	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	900.1K	¥1,788.5	-2.0%	¥1.6B ($10.4M)
2024-12-05	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	1.5M	¥1,788.5	-2.0%	¥2.6B ($16.9M)
2024-12-05	BUY	Market Buy	ブラックロック・アドバイザーズ・エルエルシー(BlackRock Advisers BlackRock Advisers, LLC	passive	462.0K	¥1,788.5	-2.0%	¥826M ($5.3M)
2024-12-05	BUY	Market Buy	アペリオ・グループ・エルエルシー(Aperio Group Aperio Group, LLC	passive	378.5K	¥1,788.5	-2.0%	¥677M ($4.4M)
2024-12-05	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	7.0M	¥1,788.5	-2.0%	¥12.6B ($81.2M)
2024-10-18	SELL	unknown	ブラック・クリーク・インベストメント・マネジメント・インク(Black Creek Investment Management, Inc.) Black Creek Investment Management, Inc.	other	13.7M	¥1,802.5	+2.8%	¥9.4B ($61.0M)
2024-07-29	BUY	Market Buy	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	7.0M	¥1,788.5	-2.0%	¥391M ($2.5M)
2024-07-29	BUY	Market Buy	ファースト・センティア・インベスターズ・アールキューアイ・ピーティーワイ・リミテッド First Sentier Investors RQI Pty Ltd	passive	482.3K	¥1,788.5	-2.0%	¥863M ($5.6M)
2024-07-29	BUY	Market Buy	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	2.2M	¥1,788.5	-2.0%	¥65M ($420K)
2024-07-29	BUY	Market Buy	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	9.8M	¥1,788.5	-2.0%	¥17.6B ($113.5M)
2024-06-06	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	19.1M	¥1,628	+7.6%	¥30.8B ($198.8M)
2024-06-06	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	171.1K	¥1,628	+7.6%	¥17.8B ($114.7M)
2024-06-06	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	221.0K	¥1,628	-7.6%	¥889M ($5.7M)
2024-04-22	BUY	subscription	シルチェスター・インターナショナル・インベスターズ・エルエルピー (Silchester International Investors LLP) Silchester International Investors LLP	activist	18.3M	¥1,471	+19.1%	¥26.9B ($173.6M)
2024-03-18	SELL	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	7.0M	¥1,447	-21.1%	¥2.9B ($19.0M)
2024-03-18	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	112.3K	¥1,447	+21.1%	¥15.7B ($101.4M)
2024-03-18	SELL	negotiated	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	2.3M	¥1,447	-21.1%	¥762M ($4.9M)
2024-03-18	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	10.1M	¥1,447	-21.1%	¥2.8B ($17.9M)
2023-11-07	SELL	Market Buy	MFSインベストメント・マネジメント株式会社 MFS Investment Management K.K.	passive	848.2K	¥1,305	-34.3%	¥245M ($1.6M)
2023-11-07	BUY	Market Buy	マサチューセッツ・ファイナンシャル・サービセズ・カンパニー Massachusetts Financial Services Company	passive	13.8M	¥1,305	+34.3%	¥17.8B ($114.6M)
2023-09-22	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	22.9M	¥1,400	+25.1%	¥31.7B ($204.7M)
2023-09-22	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	59.5K	¥1,400	+25.1%	¥10.6B ($68.2M)
2023-09-22	SELL	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	795.5K	¥1,400	-25.1%	¥1.6B ($10.2M)
2023-09-06	SELL	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	8.2M	¥1,381	-26.9%	¥3.0B ($19.1M)
2023-09-06	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	11.3M	¥1,381	-26.9%	¥2.7B ($17.4M)
2023-04-07	BUY	Market Buy	MFSインベストメント・マネジメント株式会社 MFS Investment Management K.K.	passive	1.1M	¥1,109	+58.0%	¥1.2B ($7.6M)
2023-04-07	BUY	Market Buy	マサチューセッツ・ファイナンシャル・サービセズ・カンパニー Massachusetts Financial Services Company	passive	18.6M	¥1,109	+58.0%	¥20.6B ($133.1M)
2023-04-06	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	26.1M	¥1,113	+57.4%	¥3.8B ($24.6M)
2023-04-06	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	-30.0K	¥1,113	-57.4%	¥1.5B ($10.0M)
2023-04-06	BUY	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	1.9M	¥1,113	+57.4%	¥2.1B ($13.8M)
2023-04-03	BUY	negotiated	三菱UFJ国際投信株式会社 Mitsubishi UFJ Financial Group Inc.	passive	2.9M	¥1,126	+55.6%	¥44M ($282K)
2023-04-03	SELL	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	9.3M	¥1,126	-55.6%	¥743M ($4.8M)
2023-04-03	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.	other	430.1K	¥1,126	-55.6%	¥1.5B ($9.6M)
2023-04-03	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	12.5M	¥1,126	-55.6%	¥2.0B ($13.0M)
2023-03-06	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.	other	1.7M	¥1,049	-67.0%	¥3.9B ($25.0M)
2023-03-06	BUY	Market Buy	マサチューセッツ・ファイナンシャル・サービセズ・カンパニー Massachusetts Financial Services Company	passive	17.7M	¥1,049	+67.0%	¥18.3B ($118.3M)
2023-03-06	BUY	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	10.0M	¥1,049	+67.0%	¥10.4B ($67.4M)
2023-03-06	BUY	negotiated	三菱UFJ国際投信株式会社 Mitsubishi UFJ Financial Group Inc.	passive	2.8M	¥1,049	+67.0%	¥3.0B ($19.2M)
2023-03-06	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	14.2M	¥1,049	-67.0%	¥285M ($1.8M)
2023-03-06	BUY	Market Buy	MFSインベストメント・マネジメント株式会社 MFS Investment Management K.K.	passive	1.1M	¥1,049	+67.0%	¥1.1B ($7.2M)
2023-02-21	SELL	Market Buy	MFSインベストメント・マネジメント株式会社 MFS Investment Management K.K.	passive	1.1M	¥1,042	-68.1%	¥81M ($522K)

Showing the 50 most recent of 86 filings.

Frequently asked questions

Who has been buying Santen Pharmaceutical Co., Ltd. stock?: 24 distinct investors have filed 46 disclosed large-shareholding filings in Santen Pharmaceutical Co., Ltd. (4536), most recently on 2025-10-08. 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 Santen Pharmaceutical Co., Ltd. have?: Santen Pharmaceutical Co., Ltd. has 46 buy-side and 29 sell-side disclosures on record, covering ¥333.5B ($2.2B) in total reported value, spanning 2021-10-20 to 2025-10-08.
Where does StockDrifts get Santen Pharmaceutical 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 Santen Pharmaceutical Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.