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

5 distinct investors have filed 19 disclosed large-shareholding filings in Tamron Co.,Ltd. (7740), most recently on 2026-04-07. 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 Tamron Co.,Ltd. have?

Tamron Co.,Ltd. has 19 buy-side and 0 sell-side disclosures on record, covering ¥2.1B ($13.7M) in total reported value, spanning 2021-03-19 to 2026-04-07.

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.

Tamron Co.,Ltd. 7740

Company

株式会社タムロンTamron Co.,Ltd.

Investors

Buys

Total Value

¥2.1B ($13.7M)

Avg Return

+145.81%

Last Filing

2026-04-07

Tamron Co.,Ltd. (7740) has 19 disclosed large-shareholding filings and 0 disclosed disposals on record, filed by 5 distinct investors. Together those filings cover ¥2.1B ($13.7M) in reported transaction value. The earliest filing StockDrifts holds for Tamron Co.,Ltd. is dated 2021-03-19; the most recent is 2026-04-07. Across these filings the average return since disclosure is +145.81%, 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
2026-04-07	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	29.7M	¥1,049	+28.0%	¥1.9B ($12.0M)
2026-03-11	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	27.9M	¥1,004	+33.8%	¥1.8B ($11.5M)
2026-02-17	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	26.1M	¥1,028	+30.6%	¥2.1B ($13.4M)
2025-12-10	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	24.1M	¥1,038	+29.4%	¥1.9B ($12.1M)
2025-10-23	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	22.3M	¥1,081	+24.2%	¥1.9B ($12.2M)
2025-08-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	20.6M	¥935	+43.6%	¥1.9B ($12.1M)
2025-06-20	BUY	Market Buy	りそなアセットマネジメント株式会社 Resona Asset Management Co., Ltd.	other	522.4K	¥851.25	+57.8%	¥196M ($1.3M)
2025-06-20	BUY	Market Buy	株式会社埼玉りそな銀行 Saitama Resona Bank, Limited	strategic	2.0M	¥851.25	+57.8%	¥134M ($868K)
2025-06-20	BUY	Market Buy	りそなリース株式会社 Resona Lease Co., Ltd.	strategic	100.0K	¥851.25	-	¥85M ($549K)
2023-12-20	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.5M	¥640	+109.8%	¥93M ($599K)
2023-10-03	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥560.63	-	-
2023-10-02	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥566.25	-	-
2023-09-28	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥578.75	-	-
2023-09-11	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥553.75	-	-
2023-08-25	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥547.5	-	-
2023-08-22	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥581.88	-	-
2023-08-15	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥601.25	-	-
2023-08-14	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥585.63	-	-
2023-08-10	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥588.75	-	-
2023-08-02	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥561.88	-	-
2023-07-20	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥528.13	-	-
2023-07-13	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥488.13	-	-
2023-07-11	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥491.88	+173.0%	¥76M ($490K)
2023-06-21	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥500	-	-
2023-06-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥453.75	-	-
2023-03-22	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥381.88	-	-
2023-03-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥406.25	-	-
2023-02-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.4M	¥399.38	+236.3%	¥24M ($155K)
2022-06-21	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.3M	¥315	+326.4%	¥50M ($320K)
2022-03-22	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.2M	¥295.88	-	-
2022-03-04	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.2M	¥281.38	-	-
2022-02-04	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.2M	¥316.75	-	-
2021-12-21	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.2M	¥347.25	+286.8%	¥6M ($39K)
2021-08-05	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.2M	¥339.63	+295.4%	¥8M ($55K)
2021-07-21	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.1M	¥308.25	+335.7%	¥21M ($134K)
2021-07-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	2.1M	¥315.63	+325.5%	¥111M ($718K)
2021-04-06	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	1.8M	¥235.439	+470.4%	¥47M ($304K)
2021-04-05	BUY	Market Buy	ソニーグループ株式会社 Sony Group Corporation	strategic	3.1M	¥237.646	+465.1%	¥60M ($386K)
2021-03-19	BUY	Market Buy	エフィッシモキャピタルマネージメントピーティーイーエルティーディー(Effissimo Capital Management Pte. Ltd.) Effissimo Capital Management Pte. Ltd.	passive	1.6M	¥227.14	+491.3%	¥359M ($2.3M)

Frequently asked questions

Who has been buying Tamron Co.,Ltd. stock?: 5 distinct investors have filed 19 disclosed large-shareholding filings in Tamron Co.,Ltd. (7740), most recently on 2026-04-07. 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 Tamron Co.,Ltd. have?: Tamron Co.,Ltd. has 19 buy-side and 0 sell-side disclosures on record, covering ¥2.1B ($13.7M) in total reported value, spanning 2021-03-19 to 2026-04-07.
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.