Who has been buying Sumitomo Bakelite Company Limited stock?

13 distinct investors have filed 22 disclosed large-shareholding filings in Sumitomo Bakelite Company Limited (4203), most recently on 2025-12-22. 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 Sumitomo Bakelite Company Limited have?

Sumitomo Bakelite Company Limited has 22 buy-side and 12 sell-side disclosures on record, covering ¥69.7B ($449.6M) in total reported value, spanning 2021-10-06 to 2025-12-22.

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.

Sumitomo Bakelite Company Limited 4203

Company

住友ベークライト株式会社Sumitomo Bakelite Company Limited

Investors

Buys

Total Value

¥69.7B ($449.6M)

Avg Return

+48.72%

Last Filing

2025-12-22

Sumitomo Bakelite Company Limited (4203) has 22 disclosed large-shareholding filings and 12 disclosed disposals on record, filed by 13 distinct investors. Together those filings cover ¥69.7B ($449.6M) in reported transaction value. The earliest filing StockDrifts holds for Sumitomo Bakelite Company Limited is dated 2021-10-06; the most recent is 2025-12-22. Across these filings the average return since disclosure is +48.72%, 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
2026-08-21	BUY	Market Buy	アセットマネジメントOne株式会社	other	5.9M	¥7,171	+14.1%	¥6.4B ($41.2M)
2026-08-21	SELL	unknown	みずほ証券株式会社	other	122.4K	¥7,171	-14.1%	¥570M ($3.7M)
2026-08-21	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	3.7K	¥7,171	-14.1%	¥1.4B ($9.0M)
2026-05-22	SELL	Market Buy	GICプライベート・リミテッド(GIC Private Limited) GIC Private Limited	passive	5.3M	¥6,765	-21.0%	¥6.2B ($40.1M)
2026-05-22	SELL	Market Buy	キャピタル・リサーチ・アンド・マネージメント・カンパニー(Capital Research and Management Company) Capital Research and Management Company	passive	5.2M	¥6,765	-21.0%	¥7.0B ($45.4M)
2025-12-22	SELL	unknown	アセットマネジメントOne株式会社	other	5.4M	¥5,287	-54.8%	¥5.5B ($35.5M)
2025-12-22	BUY	unknown	みずほ証券株式会社	other	216.4K	¥5,287	-	¥1.1B ($7.4M)
2025-12-22	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	203.7K	¥5,287	-54.8%	¥149M ($959K)
2025-09-29	SELL	Market Buy	GICプライベート・リミテッド(GIC Private Limited) GIC Private Limited	passive	6.6M	¥4,961	-65.0%	¥4.7B ($30.6M)
2025-09-22	BUY	Market Buy	キャピタル・リサーチ・アンド・マネージメント・カンパニー(Capital Research and Management Company) Capital Research and Management Company	passive	6.7M	¥5,133	+59.4%	¥6.1B ($39.1M)
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	1.2M	¥5,047	-62.1%	¥237M ($1.5M)
2025-09-19	BUY	unknown	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	other	1.3M	¥5,047	-	-
2025-09-19	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	2.3M	¥5,047	+62.1%	¥47M ($305K)
2025-04-16	BUY	Market Buy	GICプライベート・リミテッド(GIC Private Limited) GIC Private Limited	passive	7.5M	¥3,147	+160.0%	¥3.2B ($20.4M)
2025-02-06	SELL	Market Buy	野村證券株式会社 Nomura Securities Co.,Ltd.	other	105.9K	¥3,588	-128.1%	¥37.0B ($238.7M)
2025-02-06	SELL	unknown	住友化学株式会社 SUMITOMO CHEMICAL COMPANY, LIMITED	strategic	9.3M	¥3,588	-128.1%	¥18.8B ($121.5M)
2025-02-06	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	160.9K	¥3,588	-	¥577M ($3.7M)
2025-02-06	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	6.3M	¥3,588	+128.1%	¥3.3B ($21.3M)
2024-11-08	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	6.4M	¥4,145	+97.4%	¥4.2B ($26.8M)
2024-11-08	SELL	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	232.8K	¥4,145	-97.4%	¥466M ($3.0M)
2024-11-07	BUY	unknown	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	other	1.3M	¥4,204	+94.7%	¥5.5B ($35.5M)
2024-11-07	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	2.3M	¥4,204	+94.7%	¥9.7B ($62.7M)
2024-11-07	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	1.2M	¥4,204	+94.7%	¥5.0B ($32.5M)
2024-09-25	BUY	acquisition	GICプライベート・リミテッド(GIC Private Limited) GIC Private Limited	passive	6.5M	¥3,967	+106.3%	¥25.9B ($166.8M)
2024-09-24	SELL	unknown	住友化学株式会社 SUMITOMO CHEMICAL COMPANY, LIMITED	strategic	14.5M	¥3,951	-107.1%	¥21.2B ($136.7M)
2024-08-06	BUY	Market Buy	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	other	1.3M	¥3,656	+123.8%	¥274M ($1.8M)
2024-08-06	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	2.2M	¥3,656	-123.8%	¥3.6B ($23.0M)
2024-08-06	BUY	Market Buy	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	1.1M	¥3,656	+123.8%	¥823M ($5.3M)
2024-05-09	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	5.4M	¥4,554	+79.7%	¥4.3B ($27.5M)
2024-05-09	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	345.9K	¥4,554	+79.7%	¥43M ($275K)
2024-04-04	BUY	unknown	野村證券株式会社 Nomura Securities Co.,Ltd.	other	207.9K	¥4,550	-	¥946M ($6.1M)
2024-04-04	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	5.4M	¥4,550	+79.8%	¥24.2B ($156.4M)
2023-12-07	BUY	Market Buy	キャピタル・リサーチ・アンド・マネージメント・カンパニー(Capital Research and Management Company) Capital Research and Management Company	passive	2.7M	¥3,657.5	+123.7%	¥10.0B ($64.8M)
2023-10-20	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.4M	¥3,329.5	+145.8%	¥7.9B ($50.7M)
2023-10-20	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	176.8K	¥3,329.5	+145.8%	¥589M ($3.8M)
2023-08-04	SELL	unknown	三井住友信託銀行株式会社 Sumitomo Mitsui Trust Bank,Limited	other	654.9K	¥3,015.5	-171.4%	¥658M ($4.2M)
2023-08-04	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	1.7M	¥3,015.5	-171.4%	¥1.0B ($6.5M)
2023-08-04	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	455.4K	¥3,015.5	+171.4%	¥105M ($675K)
2023-05-24	BUY	Market Buy	住友化学株式会社 SUMITOMO CHEMICAL COMPANY, LIMITED	strategic	10.5M	¥2,710	+202.0%	¥1.6B ($10.1M)
2022-12-06	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	3.4M	¥2,115	+286.9%	¥7.1B ($46.0M)
2022-12-06	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	30.8K	¥2,115	+286.9%	¥6.2B ($39.9M)
2022-01-21	SELL	unknown	フィデリティ投信株式会社 FIL Investments (Japan) Limited	other	2.2M	¥2,880	-184.1%	¥1.5B ($9.8M)
2021-10-06	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	52.7K	¥2,400	-	¥126M ($815K)
2021-10-06	BUY	unknown	野村アセットマネジメント株式会社 Nomura Asset Management Co., Ltd.	other	3.9M	¥2,400	+241.0%	¥9.3B ($60.1M)

Frequently asked questions

Who has been buying Sumitomo Bakelite Company Limited stock?: 13 distinct investors have filed 22 disclosed large-shareholding filings in Sumitomo Bakelite Company Limited (4203), most recently on 2025-12-22. 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 Sumitomo Bakelite Company Limited have?: Sumitomo Bakelite Company Limited has 22 buy-side and 12 sell-side disclosures on record, covering ¥69.7B ($449.6M) in total reported value, spanning 2021-10-06 to 2025-12-22.
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.

More on this data

Every trade listed above comes from an official regulatory disclosure. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.