Who has been buying Obayashi Corporation stock?

24 distinct investors have filed 24 disclosed large-shareholding filings in Obayashi Corporation (1802), most recently on 2025-09-19. 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 Obayashi Corporation have?

Obayashi Corporation has 24 buy-side and 21 sell-side disclosures on record, covering ¥56.4B ($364.0M) in total reported value, spanning 2021-03-29 to 2025-09-19.

Where does StockDrifts get Obayashi 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.

Obayashi Corporation 1802

Company

株式会社大林組Obayashi Corporation

Investors

Buys

Total Value

¥56.4B ($364.0M)

Avg Return

+185.42%

Last Filing

2025-09-19

Obayashi Corporation (1802) has 24 disclosed large-shareholding filings and 21 disclosed disposals on record, filed by 24 distinct investors. Together those filings cover ¥56.4B ($364.0M) in reported transaction value. The earliest filing StockDrifts holds for Obayashi Corporation is dated 2021-03-29; the most recent is 2025-09-19. 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 +185.42%, 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
2026-07-06	SELL	unknown	野村アセットマネジメント株式会社	other	36.3M	¥3,405	+7.8%	¥13.7B ($88.1M)
2026-07-06	SELL	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	-173.9K	¥3,405	-	-
2026-07-06	SELL	unknown	野村證券株式会社	other	191.7K	¥3,405	+7.8%	¥3.5B ($22.8M)
2026-07-06	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	4.6M	¥3,405	-7.8%	¥10.6B ($68.4M)
2026-07-06	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, N.A.	passive	11.8M	¥3,405	-7.8%	¥5.2B ($33.4M)
2026-07-06	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	15.5M	¥3,405	-7.8%	¥3.5B ($22.8M)
2026-07-06	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	6.4M	¥3,405	-7.8%	¥1.6B ($10.6M)
2026-07-06	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	1.9M	¥3,405	-7.8%	¥2.4B ($15.2M)
2026-07-06	BUY	Market Buy	ブラックロック(ルクセンブルグ)エス・エーS.A.) BlackRock (Luxembourg	passive	2.8M	¥3,405	-7.8%	¥6.4B ($41.0M)
2026-07-06	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	2.2M	¥3,405	-7.8%	¥7.4B ($47.7M)
2026-07-06	BUY	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	2.3M	¥3,405	-7.8%	¥471M ($3.0M)
2026-07-06	BUY	Market Buy	ブラックロック・インベストメント・マネジメント (オーストラリア)リミテッドLimited) BlackRock Investment Management (Australia	passive	1.4M	¥3,405	-7.8%	¥1.4B ($9.1M)
2026-07-06	BUY	Market Buy	ブラックロック・インベストメント・マネジメント・エルエルシー BlackRock Investment Management LLC	passive	791.6K	¥3,405	-7.8%	¥236M ($1.5M)
2026-07-06	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, LLC	passive	2.3M	¥3,405	-7.8%	¥3.3B ($21.3M)
2026-07-06	SELL	Market Buy	ブラックロック・ジャパン株式会社	passive	13.7M	¥3,405	+7.8%	¥5.9B ($38.0M)
2026-07-06	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, Inc.	passive	2.8M	¥3,405	-7.8%	¥2.1B ($13.7M)
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	18.2M	¥2,469.5	+50.8%	¥7.5B ($48.4M)
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	22.6M	¥2,469.5	-50.8%	¥1.7B ($11.3M)
2025-09-18	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	1.5M	¥2,468.5	+50.9%	¥1.6B ($10.1M)
2025-09-18	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	10.5M	¥2,468.5	+50.9%	¥2.8B ($18.0M)
2025-09-18	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	14.8M	¥2,468.5	+50.9%	¥524M ($3.4M)
2025-09-18	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	6.1M	¥2,468.5	+50.9%	¥4.4B ($28.1M)
2025-09-18	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	1.3M	¥2,468.5	+50.9%	¥698M ($4.5M)
2025-09-18	BUY	Market Buy	ブラックロック(ルクセンブルグ)エス・エーS.A.) BlackRock (Luxembourg	passive	998.2K	¥2,468.5	+50.9%	¥2.5B ($15.9M)
2025-09-18	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	2.2M	¥2,468.5	+50.9%	¥1.0B ($6.8M)
2025-09-18	SELL	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	2.2M	¥2,468.5	-50.9%	¥2.1B ($13.5M)
2025-09-18	BUY	Market Buy	ブラックロック・インベストメント・マネジメント (オーストラリア)リミテッドLimited) BlackRock Investment Management (Australia	passive	1.1M	¥2,468.5	+50.9%	¥2.6B ($17.0M)
2025-09-18	BUY	Market Buy	ブラックロック・インベストメント・マネジメント・エルエルシー BlackRock Investment Management LLC	passive	723.6K	¥2,468.5	+50.9%	¥1.8B ($11.5M)
2025-09-18	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	2.3M	¥2,468.5	+50.9%	¥3.1B ($20.3M)
2025-09-18	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	1.3M	¥2,468.5	+50.9%	¥3.2B ($20.9M)
2025-09-18	SELL	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	15.8M	¥2,468.5	-50.9%	¥3.5B ($22.5M)
2024-05-08	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	978.7K	¥1,727	+115.6%	¥374M ($2.4M)
2024-05-08	SELL	Market Buy	ブラックロック(ネザーランド)BVBV) BlackRock (Netherlands	passive	3.1M	¥1,727	-115.6%	¥748M ($4.8M)
2024-05-08	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	865.3K	¥1,727	-115.6%	¥1.2B ($8.0M)
2024-05-08	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	9.6M	¥1,727	-115.6%	¥623M ($4.0M)
2024-05-08	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	14.9M	¥1,727	+115.6%	¥5.7B ($37.0M)
2024-05-08	SELL	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	4.4M	¥1,727	-115.6%	¥1.1B ($7.2M)
2024-05-08	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	1.8M	¥1,727	-115.6%	¥872M ($5.6M)
2024-05-08	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	998.2K	¥1,727	+115.6%	¥1.7B ($11.1M)
2024-05-08	BUY	Market Buy	ブラックロック・ジャパン株式会社 BlackRock Japan Co., Ltd.	passive	17.5M	¥1,727	+115.6%	¥11.3B ($73.2M)
2024-01-09	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	42.0M	¥1,263.5	+194.7%	¥7.5B ($48.2M)
2024-01-09	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	1.8M	¥1,263.5	+194.7%	¥2.3B ($14.7M)
2024-01-09	BUY	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	1.3M	¥1,263.5	+194.7%	¥1.6B ($10.6M)
2023-09-22	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	15.4M	¥1,366.5	+172.5%	¥394M ($2.5M)
2023-09-22	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	23.7M	¥1,366.5	-172.5%	¥5.0B ($32.4M)
2023-02-20	SELL	negotiated	エム・ユー投資顧問株式会社 M.U. Investment Advisors Co., Ltd.	passive	659.8K	¥978	-280.8%	¥141M ($910K)
2023-02-20	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	383.9K	¥978	-280.8%	¥635M ($4.1M)
2023-02-20	SELL	negotiated	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	23.4M	¥978	-280.8%	¥4.0B ($25.5M)
2023-02-20	SELL	negotiated	株式会社三菱UFJ銀行 Mitsubishi UFJ Financial Group Inc.	strategic	690.7K	¥978	-280.8%	¥1.5B ($9.6M)
2023-02-20	BUY	negotiated	三菱UFJ国際投信株式会社 Mitsubishi UFJ Financial Group Inc.	passive	8.4M	¥978	+280.8%	¥635M ($4.1M)

Showing the 50 most recent of 78 filings.

Frequently asked questions

Who has been buying Obayashi Corporation stock?: 24 distinct investors have filed 24 disclosed large-shareholding filings in Obayashi Corporation (1802), most recently on 2025-09-19. 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 Obayashi Corporation have?: Obayashi Corporation has 24 buy-side and 21 sell-side disclosures on record, covering ¥56.4B ($364.0M) in total reported value, spanning 2021-03-29 to 2025-09-19.
Where does StockDrifts get Obayashi 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 Obayashi Corporation. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.