Who has been buying Sumco Corporation stock?

42 distinct investors have filed 179 disclosed large-shareholding filings in Sumco Corporation (3436), most recently on 2026-05-08. 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 Sumco Corporation have?

Sumco Corporation has 179 buy-side and 136 sell-side disclosures on record, covering ¥1.06T ($6.9B) in total reported value, spanning 2021-06-04 to 2026-05-08.

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.

Sumco Corporation 3436

Company

株式会社ＳＵＭＣＯSumco Corporation

Investors

Buys

179

Total Value

¥1.06T ($6.9B)

Avg Return

+24.25%

Last Filing

2026-05-08

Sumco Corporation (3436) has 179 disclosed large-shareholding filings and 136 disclosed disposals on record, filed by 42 distinct investors. Together those filings cover ¥1.06T ($6.9B) in reported transaction value. The earliest filing StockDrifts holds for Sumco Corporation is dated 2021-06-04; the most recent is 2026-05-08. Across these filings the average return since disclosure is +24.25%, 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
2026-09-04	SELL	unknown	野村アセットマネジメント株式会社	other	15.3M	¥3,229	+10.2%	¥17.2B ($110.9M)
2026-09-04	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	1.2M	¥3,229	-10.2%	¥905M ($5.8M)
2026-09-04	BUY	unknown	野村證券株式会社	other	1.1M	¥3,229	-	¥3.6B ($23.2M)
2026-07-23	SELL	unknown	エフアイエーエムエルエルシー FIAM LLC	other	5.8M	¥3,744	+22.5%	¥5.9B ($38.1M)
2026-07-23	SELL	unknown	フィデリティマネジメントアンドリサーチカンパニーエルエルシー Fidelity Management & Research Company LLC	corporate	8.1M	¥3,744	+22.5%	¥7.2B ($46.5M)
2026-07-23	SELL	unknown	フィデリティマネジメントトラストカンパニー Fidelity Management Trust Company	other	787.6K	¥3,744	+22.5%	¥1.3B ($8.5M)
2026-07-23	BUY	Market Buy	フィデリティインスティテューショナルアセットマネジメントトラストカンパニー Fidelity Institutional Asset Management Trust Company	other	1.3M	¥3,744	-22.5%	¥787M ($5.1M)
2026-06-19	BUY	Market Buy	フィデリティマネジメントアンドリサーチカンパニーエルエルシー Fidelity Management & Research Company LLC	corporate	10.1M	¥4,254	-31.8%	¥745M ($4.8M)
2026-06-19	BUY	Market Buy	エフアイエーエムエルエルシー FIAM LLC	other	7.4M	¥4,254	-31.8%	¥6.6B ($42.3M)
2026-06-19	BUY	unknown	フィデリティマネジメントトラストカンパニー Fidelity Management Trust Company	other	1.1M	¥4,254	-	-
2026-06-19	BUY	Market Buy	フィデリティインスティテューショナルアセットマネジメントトラストカンパニー Fidelity Institutional Asset Management Trust Company	other	1.1M	¥4,254	-31.8%	¥298M ($1.9M)
2026-06-19	BUY	unknown	エフエムアールインベストメントマネジメントユーケーリミテッドLimited) FMR Investment Management (UK	other	394.7K	¥4,254	-	¥1.7B ($10.8M)
2026-06-19	BUY	unknown	フィデリティマネジメントアンドリサーチカンパニーエルエルシー Fidelity Management & Research Company LLC	corporate	9.9M	¥4,254	-	-
2026-06-19	BUY	Market Buy	フィデリティマネジメントトラストカンパニー Fidelity Management Trust Company	other	1.1M	¥4,254	-31.8%	¥149M ($961K)
2026-06-19	BUY	unknown	フィデリティインスティテューショナルアセットマネジメントトラストカンパニー Fidelity Institutional Asset Management Trust Company	other	1.1M	¥4,254	-	-
2026-06-19	BUY	unknown	エフアイエーエムエルエルシー FIAM LLC	other	5.9M	¥4,254	-	-
2026-06-09	BUY	unknown	フィデリティマネジメントアンドリサーチカンパニーエルエルシー Fidelity Management & Research Company LLC	corporate	9.9M	¥3,501	-17.1%	¥34.6B ($223.3M)
2026-06-09	BUY	unknown	フィデリティマネジメントトラストカンパニー Fidelity Management Trust Company	other	1.1M	¥3,501	-17.1%	¥3.8B ($24.6M)
2026-06-09	BUY	unknown	フィデリティインスティテューショナルアセットマネジメントトラストカンパニー Fidelity Institutional Asset Management Trust Company	other	1.1M	¥3,501	-17.1%	¥3.7B ($24.0M)
2026-06-09	BUY	unknown	エフアイエーエムエルエルシー FIAM LLC	other	5.9M	¥3,501	-17.1%	¥20.6B ($132.8M)
2026-06-04	SELL	unknown	野村證券株式会社	other	75.4K	¥4,366	+33.6%	¥12.8B ($82.9M)
2026-06-04	SELL	unknown	野村アセットマネジメント株式会社	other	20.6M	¥4,366	+33.6%	¥11.6B ($75.0M)
2026-06-04	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	917.6K	¥4,366	-	¥4.0B ($25.8M)
2026-05-08	SELL	Market Buy	イーストスプリング・インベストメンツ(シンガポール)リミテッド(Eastspring Investments (Singapore) Limited) Eastspring Investments (Singapore) Limited	passive	15.7M	¥3,578	+18.9%	¥23.7B ($152.8M)
2026-04-21	BUY	Market Buy	野村證券株式会社	other	3.0M	¥2,226	+30.3%	¥5.8B ($37.2M)
2026-04-21	SELL	unknown	野村アセットマネジメント株式会社	other	23.3M	¥2,226	-30.3%	¥3.2B ($20.6M)
2026-04-21	SELL	unknown	三井住友トラスト・アセットマネジメント株式会社	other	9.3M	¥2,226	-30.3%	¥312M ($2.0M)
2026-04-21	SELL	unknown	アモーヴァ・アセットマネジメント株式会社	other	11.6M	¥2,226	-30.3%	¥935M ($6.0M)
2026-04-21	SELL	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	¥2,226	-37.8%	¥8.7B ($56.3M)
2026-04-06	SELL	unknown	野村證券株式会社	other	423.8K	¥1,746	-66.1%	¥2.2B ($14.2M)
2026-04-06	BUY	unknown	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	2.1M	¥1,746	-	¥3.7B ($23.7M)
2026-04-06	SELL	unknown	野村アセットマネジメント株式会社	other	24.7M	¥1,746	-66.1%	¥367M ($2.4M)
2026-03-19	SELL	Market Buy	ノムラインターナショナルピーエルシー NOMURA INTERNATIONAL PLC	other	-622.6K	¥1,682.5	-25.4%	¥1.3B ($8.5M)
2026-03-19	BUY	Market Buy	野村證券株式会社	other	1.7M	¥1,682.5	+72.4%	¥1.3B ($8.4M)
2026-03-19	BUY	Market Buy	野村アセットマネジメント株式会社	other	24.9M	¥1,682.5	+72.4%	¥236M ($1.5M)
2026-02-19	SELL	unknown	三井住友トラスト・アセットマネジメント株式会社	other	9.4M	¥1,623	-78.7%	¥3.2B ($20.5M)
2026-02-19	BUY	unknown	アモーヴァ・アセットマネジメント株式会社	other	12.0M	¥1,623	+78.7%	¥114M ($733K)
2026-02-06	BUY	Market Buy	野村證券株式会社 Nomura Securities Co.,Ltd.	other	28.6M	¥1,624.5	+78.5%	¥11.9B ($77.1M)
2026-02-06	SELL	unknown	ゴールドマン・サックス証券株式会社 Goldman Sachs Japan Co.,Ltd.	other	14.1M	¥1,624.5	-78.5%	¥8.4B ($53.9M)
2026-01-22	BUY	Market Buy	ナショナルファイナンシャルサービスエルエルシー National Financial Services LLC	other	3.4K	¥1,696	-	-
2026-01-22	BUY	Market Buy	エフエムアールエルエルシー FMR LLC	other	20.1M	¥1,696	+71.0%	¥3.3B ($21.5M)
2026-01-22	BUY	Market Buy	エフエムアールエルエルシー FMR LLC	other	20.1M	¥1,696	+71.0%	¥3.3B ($21.5M)
2026-01-22	BUY	unknown	ナショナルファイナンシャルサービスエルエルシー National Financial Services LLC	other	3.4K	¥1,696	-	-
2026-01-21	SELL	unknown	三井住友トラスト・アセットマネジメント株式会社	other	11.4M	¥1,594	-82.0%	¥112M ($720K)
2026-01-21	BUY	unknown	アモーヴァ・アセットマネジメント株式会社	other	11.9M	¥1,594	-	-
2026-01-21	SELL	Market Buy	野村證券株式会社	other	104.2K	¥1,594	-82.0%	¥223M ($1.4M)
2026-01-21	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	922.9K	¥1,594	+82.0%	¥893M ($5.8M)
2026-01-21	BUY	Market Buy	野村アセットマネジメント株式会社	other	20.2M	¥1,594	+82.0%	¥1.0B ($6.5M)
2026-01-09	BUY	unknown	エフエムアールエルエルシー FMR LLC	other	18.2M	¥1,489	-	-
2026-01-09	BUY	unknown	ナショナルファイナンシャルサービスエルエルシー National Financial Services LLC	other	8.5K	¥1,489	-	-

Showing the 50 most recent of 200 filings.

Frequently asked questions

Who has been buying Sumco Corporation stock?: 42 distinct investors have filed 179 disclosed large-shareholding filings in Sumco Corporation (3436), most recently on 2026-05-08. 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 Sumco Corporation have?: Sumco Corporation has 179 buy-side and 136 sell-side disclosures on record, covering ¥1.06T ($6.9B) in total reported value, spanning 2021-06-04 to 2026-05-08.
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.