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

19 distinct investors have filed 35 disclosed large-shareholding filings in Sankyo Co., Ltd. (6417), most recently on 2026-02-20. 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 Sankyo Co., Ltd. have?

Sankyo Co., Ltd. has 35 buy-side and 22 sell-side disclosures on record, covering ¥44.0B ($283.6M) in total reported value, spanning 2021-04-08 to 2026-02-20.

Where does StockDrifts get Sankyo 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.

Sankyo Co., Ltd. 6417

Company

株式会社三共Sankyo Co., Ltd.

Investors

Buys

Total Value

¥44.0B ($283.6M)

Avg Return

+71.18%

Last Filing

2026-02-20

Sankyo Co., Ltd. (6417) has 35 disclosed large-shareholding filings and 22 disclosed disposals on record, filed by 19 distinct investors. Together those filings cover ¥44.0B ($283.6M) in reported transaction value. The earliest filing StockDrifts holds for Sankyo Co., Ltd. is dated 2021-04-08; the most recent is 2026-02-20. 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 +71.18%, 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
2026-02-20	BUY	Market Buy	コロンビア・スレッドニードル・インベストメント・ビジネス・リミテッド Columbia Threadneedle Investment Business Limited	passive	1.2M	¥2,172.5	+9.5%	¥2.4B ($15.2M)
2026-02-20	SELL	Market Buy	コロンビア・スレッドニードル・マネジメント・リミテッド Columbia Threadneedle Management Limited	passive	14.3K	¥2,172.5	+9.5%	¥28M ($181K)
2026-02-20	SELL	Market Buy	コロンビア・マネジメント・インベストメント・アドバイザーズ・エルエルシー(Columbia Management Investment Advisers	passive	12.5M	¥2,172.5	+9.5%	¥24.6B ($158.5M)
2026-02-20	SELL	Market Buy	スレッドニードル・アセット・マネジメント・リミテッド Threadneedle Asset Management Limited	passive	1.2M	¥2,172.5	+9.5%	¥2.3B ($15.0M)
2024-10-03	SELL	Market Buy	アイ・シェアーズ(デーエー)・アインツ・インベストメントアクティエンゲゼルシャフト・ミット・タイルゲゼルシャフツフェアメーゲンI Investmentaktiengesellschaft mit Teilgesellschaftsvermogen) iShares (DE	passive	0	¥2,075.5	+5.2%	¥5.0B ($32.4M)
2024-10-03	SELL	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	1.8M	¥2,075.5	+5.2%	¥1.6B ($10.1M)
2024-10-03	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	2.7M	¥2,075.5	-5.2%	¥5.5B ($35.6M)
2024-10-03	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	411.0K	¥2,075.5	-5.2%	¥54M ($348K)
2024-10-03	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	61.5K	¥2,075.5	-5.2%	¥10.2B ($65.8M)
2024-10-03	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	403.2K	¥2,075.5	-5.2%	¥54M ($348K)
2024-10-03	SELL	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	232.9K	¥2,075.5	+5.2%	¥270M ($1.7M)
2024-10-03	SELL	Market Buy	ブラックロック・フィナンシャル・マネジメント・インク(BlackRock Financial Management BlackRock Financial Management, Inc.	passive	377.3K	¥2,075.5	+5.2%	¥755M ($4.9M)
2024-10-03	SELL	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	900	¥2,075.5	+5.2%	¥594M ($3.8M)
2024-10-03	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	3.9M	¥2,075.5	-5.2%	¥324M ($2.1M)
2024-08-19	BUY	negotiated	株式会社マーフコーポレーション Murf Corporation Co., Ltd.	activist	4.0M	¥1,922	+2.3%	¥7.7B ($49.6M)
2024-08-19	BUY	negotiated	毒島秀行 Hideyuki Busujima	activist	10.2M	¥1,922	+2.3%	¥19.7B ($126.8M)
2024-07-03	BUY	Market Buy	アイ・シェアーズ(デーエー)・アインツ・インベストメントアクティエンゲゼルシャフト・ミット・タイルゲゼルシャフツフェアメーゲンI Investmentaktiengesellschaft mit Teilgesellschaftsvermogen) iShares (DE	passive	2.4M	¥1,797.5	+9.4%	¥4.3B ($28.0M)
2024-07-03	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	2.6M	¥1,797.5	+9.4%	¥4.6B ($29.9M)
2024-07-03	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	2.6M	¥1,797.5	+9.4%	¥4.8B ($30.7M)
2024-07-03	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	400.2K	¥1,797.5	+9.4%	¥719M ($4.6M)
2024-07-03	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	290.7K	¥1,797.5	+9.4%	¥523M ($3.4M)
2024-07-03	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	389.5K	¥1,797.5	+9.4%	¥700M ($4.5M)
2024-07-03	BUY	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	355.8K	¥1,797.5	+9.4%	¥640M ($4.1M)
2024-07-03	BUY	Market Buy	ブラックロック・フィナンシャル・マネジメント・インク(BlackRock Financial Management BlackRock Financial Management, Inc.	passive	757.2K	¥1,797.5	+9.4%	¥1.4B ($8.8M)
2024-07-03	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	274.3K	¥1,797.5	+9.4%	¥493M ($3.2M)
2024-07-03	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	3.7M	¥1,797.5	+9.4%	¥6.7B ($43.2M)
2024-03-06	BUY	Market Buy	スレッドニードル・アセット・マネジメント・リミテッド Threadneedle Asset Management Limited	passive	361.1K	¥1,701	+15.6%	¥212M ($1.4M)
2024-03-06	BUY	Market Buy	コロンビア・スレッドニードル・マネジメント・リミテッド Columbia Threadneedle Management Limited	passive	203.6K	¥1,701	+15.6%	¥62M ($399K)
2024-03-06	BUY	Market Buy	コロンビア・マネジメント・インベストメント・アドバイザーズ・エルエルシー(Columbia Management Investment Advisers Columbia Management Investment Advisers, LLC	passive	2.9M	¥1,701	+15.6%	¥885M ($5.7M)
2023-12-22	BUY	Market Buy	コロンビア・スレッドニードル・マネジメント・リミテッド Columbia Threadneedle Management Limited	passive	201.5K	¥1,633.4	+20.4%	¥329M ($2.1M)
2023-12-22	BUY	Market Buy	コロンビア・マネジメント・インベストメント・アドバイザーズ・エルエルシー(Columbia Management Investment Advisers Columbia Management Investment Advisers, LLC	passive	2.9M	¥1,633.4	+20.4%	¥4.7B ($30.4M)
2023-12-22	BUY	Market Buy	スレッドニードル・アセット・マネジメント・リミテッド Threadneedle Asset Management Limited	passive	277.5K	¥1,633.4	+20.4%	¥453M ($2.9M)
2023-11-15	BUY	negotiated	毒島秀行 Hideyuki Busujima	activist	1.9M	¥1,254	+56.9%	¥2.3B ($15.2M)
2023-11-15	SELL	negotiated	株式会社マーフコーポレーション Murf Corporation Co., Ltd.	activist	0	¥1,254	-56.9%	¥63M ($405K)
2023-10-26	SELL	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	2.7M	¥1,234	-59.4%	¥851M ($5.5M)
2023-10-04	SELL	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	3.3M	¥1,350.2	-45.7%	¥976M ($6.3M)
2023-09-29	SELL	negotiated	株式会社マーフコーポレーション Murf Corporation Co., Ltd.	activist	5.0M	¥1,370.8	-43.5%	¥473M ($3.1M)
2023-09-29	SELL	negotiated	毒島秀行 Hideyuki Busujima	activist	2.4M	¥1,370.8	-43.5%	¥3.2B ($20.9M)
2023-09-13	SELL	Market Buy	株式会社エスアイエル SIL Co., Ltd.	unknown	0	¥1,290.8	-52.4%	¥240M ($1.5M)
2023-09-13	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	4.1M	¥1,290.8	+52.4%	¥5.2B ($33.5M)
2023-08-18	SELL	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	184.9K	¥1,242.8	-58.3%	¥82M ($532K)
2023-08-18	SELL	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	unknown	0	¥1,242.8	-58.3%	¥759M ($4.9M)
2023-08-18	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	4.6M	¥1,242.8	+58.3%	¥5.7B ($36.7M)
2023-07-26	BUY	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	249.4K	¥1,174.2	+67.5%	¥293M ($1.9M)
2023-07-26	SELL	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	612.8K	¥1,174.2	-67.5%	¥787M ($5.1M)
2023-07-26	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	4.6M	¥1,174.2	+67.5%	¥5.4B ($34.7M)
2023-06-19	SELL	Market Buy	株式会社エスアイエル SIL Co., Ltd.	passive	249.4K	¥1,182.6	-66.3%	¥785M ($5.1M)
2023-06-19	SELL	Market Buy	株式会社UH Partners 2 UH Partners 2, Inc.	passive	1.3M	¥1,182.6	-66.3%	¥282M ($1.8M)
2023-06-19	BUY	Market Buy	光通信株式会社 Hikari Tsushin K.K.	passive	4.6M	¥1,182.6	+66.3%	¥259M ($1.7M)
2023-01-13	BUY	Market Buy	毒島秀行 Hideyuki Busujima	activist	4.8M	¥988	+99.1%	¥983M ($6.3M)

Showing the 50 most recent of 68 filings.

Frequently asked questions

Who has been buying Sankyo Co., Ltd. stock?: 19 distinct investors have filed 35 disclosed large-shareholding filings in Sankyo Co., Ltd. (6417), most recently on 2026-02-20. 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 Sankyo Co., Ltd. have?: Sankyo Co., Ltd. has 35 buy-side and 22 sell-side disclosures on record, covering ¥44.0B ($283.6M) in total reported value, spanning 2021-04-08 to 2026-02-20.
Where does StockDrifts get Sankyo 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 Sankyo Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.