Who has been buying Fujisan Magazine Service Co., Ltd. stock?

7 distinct investors have filed 13 disclosed large-shareholding filings in Fujisan Magazine Service Co., Ltd. (3138), most recently on 2026-01-06. 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 Fujisan Magazine Service Co., Ltd. have?

Fujisan Magazine Service Co., Ltd. has 13 buy-side and 8 sell-side disclosures on record, covering ¥2.0B ($12.7M) in total reported value, spanning 2021-03-26 to 2026-01-06.

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.

Fujisan Magazine Service Co., Ltd. 3138

Company

株式会社富士山マガジンサービスFujisan Magazine Service Co., Ltd.

Investors

Buys

Total Value

¥2.0B ($12.7M)

Avg Return

+45.23%

Last Filing

2026-01-06

Fujisan Magazine Service Co., Ltd. (3138) has 13 disclosed large-shareholding filings and 8 disclosed disposals on record, filed by 7 distinct investors. Together those filings cover ¥2.0B ($12.7M) in reported transaction value. The earliest filing StockDrifts holds for Fujisan Magazine Service Co., Ltd. is dated 2021-03-26; the most recent is 2026-01-06. Across these filings the average return since disclosure is +45.23%, 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
2026-01-06	BUY	Market Buy	神谷アントニオ Kamiya Antonio	activist	400.3K	¥900	+29.0%	¥2M ($15K)
2026-01-06	BUY	unknown	株式会社Catalyst・Data・Partners Catalyst Data Partners Co.,Ltd.	other	307.9K	¥900	-	-
2026-01-06	SELL	unknown	株式会社Catalyst・Data・Partners Catalyst Data Partners Co.,Ltd.	unknown	0	¥900	-29.0%	¥277M ($1.8M)
2026-01-06	BUY	Market Buy	西野伸一郎	activist	877.7K	¥900	+29.0%	¥2M ($15K)
2026-01-06	BUY	Market Buy	合同会社581Wilcox Ave.	activist	206.9K	¥900	-	-
2025-12-26	BUY	unknown	株式会社ABEJA ABEJA,Inc.	other	307.9K	¥1,018	+14.1%	¥313M ($2.0M)
2024-09-17	BUY	subscription	神谷アントニオ Kamiya Antonio	activist	397.6K	¥669	-	¥37M ($239K)
2024-09-17	SELL	subscription	西野伸一郎 Shinichiro Nishino	activist	875.0K	¥669	-73.5%	¥28M ($180K)
2024-09-17	SELL	subscription	西野伸一郎 Shinichiro Nishino	activist	875.0K	¥669	-73.5%	¥28M ($180K)
2024-09-17	SELL	subscription	神谷アントニオ Kamiya Antonio	activist	397.6K	¥669	-73.5%	¥37M ($239K)
2024-09-17	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥669	-	-
2024-09-17	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥669	-	-
2024-03-26	BUY	subscription	神谷アントニオ Kamiya Antonio	activist	461.6K	¥710	+63.5%	¥7M ($46K)
2024-02-01	BUY	subscription	西野伸一郎 Shinichiro Nishino	activist	939.0K	¥689	-	-
2024-02-01	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥689	-	-
2024-01-30	BUY	subscription	西野伸一郎 Shinichiro Nishino	activist	939.0K	¥689	+68.5%	¥2M ($10K)
2024-01-30	BUY	subscription	西野伸一郎 Shinichiro Nishino	activist	939.0K	¥689	+68.5%	¥2M ($10K)
2024-01-30	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥689	-	-
2024-01-30	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥689	-	-
2022-01-05	BUY	unknown	株式会社Catalyst・Data・Partners Catalyst Data Partners Co.,Ltd.	other	307.9K	¥840	+38.2%	¥259M ($1.7M)
2022-01-05	SELL	unknown	カルチュア・エンタテインメント株式会社 Culture Entertainment Co.,Ltd.	other	0	¥840	-38.2%	¥280M ($1.8M)
2021-12-28	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥820	-	-
2021-12-28	BUY	subscription	西野伸一郎 Shinichiro Nishino	activist	936.6K	¥820	+41.6%	¥10M ($67K)
2021-12-27	SELL	subscription	西野伸一郎 Shinichiro Nishino	activist	936.6K	¥838	-38.5%	¥77M ($495K)
2021-12-27	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	206.9K	¥838	+38.5%	¥81M ($520K)
2021-04-02	BUY	subscription	西野伸一郎 Shinichiro Nishino	activist	1.0M	¥770.467	+50.7%	¥511K ($3K)
2021-04-02	BUY	subscription	合同会社581Wilcox Ave. LLC 581 Wilcox Ave.	activist	110.9K	¥770.467	+50.7%	¥46M ($295K)
2021-04-02	BUY	subscription	神谷アントニオ Kamiya Antonio	activist	458.3K	¥770.467	+50.7%	¥178M ($1.1M)
2021-03-31	SELL	negotiated	カルチュア・エンタテインメント株式会社 Culture Entertainment Co.,Ltd.	strategic	332.9K	¥792.145	-46.6%	¥513M ($3.3M)
2021-03-31	BUY	unknown	株式会社図書館流通センター TRC Library Service Inc.	other	350.0K	¥792.145	+46.6%	¥277M ($1.8M)
2021-03-26	SELL	negotiated	カルチュア・エンタテインメント株式会社 Culture Entertainment Co.,Ltd.	strategic	980.4K	¥765.047	-51.8%	¥9M ($59K)

Frequently asked questions

Who has been buying Fujisan Magazine Service Co., Ltd. stock?: 7 distinct investors have filed 13 disclosed large-shareholding filings in Fujisan Magazine Service Co., Ltd. (3138), most recently on 2026-01-06. 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 Fujisan Magazine Service Co., Ltd. have?: Fujisan Magazine Service Co., Ltd. has 13 buy-side and 8 sell-side disclosures on record, covering ¥2.0B ($12.7M) in total reported value, spanning 2021-03-26 to 2026-01-06.
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.