Who has been buying Star Mica Holdings Co., Ltd. stock?

14 distinct investors have filed 21 disclosed large-shareholding filings in Star Mica Holdings Co., Ltd. (2975), most recently on 2025-06-30. 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 Star Mica Holdings Co., Ltd. have?

Star Mica Holdings Co., Ltd. has 21 buy-side and 18 sell-side disclosures on record, covering ¥4.9B ($31.6M) in total reported value, spanning 2021-03-22 to 2025-06-30.

Where does StockDrifts get Star Mica Holdings Co., Ltd. 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.

Star Mica Holdings Co., Ltd. 2975

Company

スター・マイカ・ホールディングス株式会社Star Mica Holdings Co., Ltd.

Investors

Buys

Total Value

¥4.9B ($31.6M)

Avg Return

+142.43%

Last Filing

2025-06-30

Star Mica Holdings Co., Ltd. (2975) has 21 disclosed large-shareholding filings and 18 disclosed disposals on record, filed by 14 distinct investors. Together those filings cover ¥4.9B ($31.6M) in reported transaction value. The earliest filing StockDrifts holds for Star Mica Holdings Co., Ltd. is dated 2021-03-22; the most recent is 2025-06-30. 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 +142.43%, 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
2026-06-05	SELL	subscription	水永政志 MASASHI MIZUNAGA	activist	11.3M	¥1,479	-2.7%	¥4.0B ($26.1M)
2026-06-02	BUY	private	東京建物株式会社 Tokyo Tatemono Co.,Ltd.	strategic	5.2M	¥1,528	+2.0%	¥8.0B ($51.4M)
2026-05-20	SELL	subscription	水永政志 MASASHI MIZUNAGA	activist	12.7M	¥1,613	+3.0%	¥286M ($1.8M)
2025-06-30	SELL	Market Buy	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	828.4K	¥991	-73.6%	¥679M ($4.4M)
2025-06-30	BUY	Market Buy	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	625.8K	¥991	+73.6%	¥14M ($89K)
2025-05-19	BUY	Market Buy	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	596.7K	¥947	+81.6%	¥351M ($2.3M)
2025-05-19	SELL	Market Buy	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	1.5M	¥947	-81.6%	¥26M ($166K)
2025-03-21	BUY	Market Buy	水永政志 Masashi Mizunaga	activist	12.6M	¥906	+89.8%	¥92M ($596K)
2024-10-18	SELL	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	16.1K	¥656	-162.2%	¥49M ($317K)
2024-10-18	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	180.3K	¥656	+162.2%	¥118M ($763K)
2024-10-18	SELL	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	899.3K	¥656	-162.2%	¥500M ($3.2M)
2024-09-20	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	308.6K	¥612	+181.1%	¥40M ($255K)
2024-09-20	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	1.2M	¥612	+181.1%	¥730M ($4.7M)
2024-09-17	BUY	Market Buy	三菱UFJアセットマネジメント株式会社 Mitsubishi UFJ Financial Group Inc.	passive	228.2K	¥594	+189.6%	¥136M ($875K)
2024-09-17	BUY	Market Buy	三菱UFJ信託銀行株式会社 Mitsubishi UFJ Financial Group Inc.	passive	1.5M	¥594	+189.6%	¥895M ($5.8M)
2024-03-22	BUY	Market Buy	水永政志 Masashi Mizunaga	activist	12.4M	¥598	+187.6%	¥413M ($2.7M)
2024-03-22	BUY	unknown	水永政志 Masashi Mizunaga	activist	12.4M	¥598	+187.6%	¥413M ($2.7M)
2023-08-04	BUY	Market Buy	三井住友DSアセットマネジメント株式会社 Sumitomo Mitsui DS Asset Management Company, Limited	passive	1.7M	¥606	+183.8%	¥1.0B ($6.7M)
2023-02-06	BUY	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	246.1K	¥667	+157.9%	¥11M ($73K)
2023-02-06	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	1.8M	¥667	-157.9%	¥98M ($629K)
2023-02-03	SELL	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	91.4K	¥665	-158.7%	¥5M ($29K)
2023-02-03	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	2.4K	¥665	+158.7%	¥133M ($861K)
2023-02-03	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	1.7M	¥665	+158.7%	¥127M ($817K)
2023-02-02	SELL	Market Buy	スパークス・アセット・マネジメント株式会社 SPARX Asset Management Co., Ltd.	passive	1.5M	¥674	-155.2%	¥520M ($3.4M)
2022-11-28	BUY	Market Buy	水永政志 Masashi Mizunaga	activist	5.9M	¥759	+126.6%	¥574M ($3.7M)
2022-09-05	BUY	Market Buy	スパークス・アセット・マネジメント株式会社 SPARX Asset Management Co., Ltd.	passive	1.1M	¥766.5	+124.4%	¥177M ($1.1M)
2022-08-19	SELL	unknown	日興アセットマネジメント株式会社 Nikko Asset Management Co.,Ltd.	other	129.4K	¥809	-112.6%	¥12M ($80K)
2022-08-19	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	1.1M	¥809	+112.6%	¥883M ($5.7M)
2022-04-20	BUY	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	55.0K	¥856.5	+100.8%	¥47M ($304K)
2022-04-20	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	79.5K	¥856.5	+100.8%	¥68M ($439K)
2022-04-20	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	833.4K	¥856.5	+100.8%	¥714M ($4.6M)
2022-04-12	SELL	unknown	田口弘 Hiroshi Taguchi	strategic	0	¥841	-104.5%	¥1.6B ($10.3M)
2022-04-12	BUY	unknown	田口弘 Hiroshi Taguchi	strategic	0	¥841	+104.5%	¥1.5B ($9.9M)
2022-01-05	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	803.9K	¥665.5	+158.4%	¥535M ($3.5M)
2022-01-05	SELL	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	61.6K	¥665.5	-158.4%	¥60M ($385K)
2022-01-05	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	300	¥665.5	+158.4%	¥200K ($1K)
2021-11-18	BUY	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	149.7K	¥691	+148.9%	¥90M ($578K)
2021-11-18	SELL	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	200	¥691	-148.9%	¥16M ($102K)
2021-11-18	SELL	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	803.9K	¥691	-148.9%	¥75M ($484K)
2021-09-22	SELL	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	8.1K	¥752	-128.7%	¥4M ($25K)
2021-09-07	SELL	Market Buy	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	96.3K	¥701	-145.4%	¥5M ($34K)
2021-09-07	BUY	Market Buy	三井住友DSアセットマネジメント株式会社 Sumitomo Mitsui DS Asset Management Company, Limited	passive	664.6K	¥701	+145.4%	¥460M ($3.0M)
2021-06-15	BUY	Market Buy	水永政志 Masashi Mizunaga	activist	5.7M	¥577.5	+197.8%	¥55M ($355K)
2021-06-07	SELL	Market Buy	ラッセル・インベストメント・インプリメンテーション・サービシーズ・エル・エル・シー(RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC) RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC	passive	683.7K	¥560	-207.1%	¥138M ($892K)
2021-05-20	SELL	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	1.3M	¥520	-230.8%	¥9M ($56K)
2021-04-22	SELL	Market Buy	ラッセル・インベストメント・インプリメンテーション・サービシーズ・エル・エル・シー(RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC) RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC	passive	929.4K	¥581	-196.0%	¥126M ($815K)
2021-03-22	SELL	Market Buy	ラッセル・インベストメント・インプリメンテーション・サービシーズ・エル・エル・シー(RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC) RUSSELL INVESTMENTS IMPLEMENTATION SERVICES, LLC	passive	1.1M	¥545.304	-215.4%	¥108M ($699K)

Frequently asked questions

Who has been buying Star Mica Holdings Co., Ltd. stock?: 14 distinct investors have filed 21 disclosed large-shareholding filings in Star Mica Holdings Co., Ltd. (2975), most recently on 2025-06-30. 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 Star Mica Holdings Co., Ltd. have?: Star Mica Holdings Co., Ltd. has 21 buy-side and 18 sell-side disclosures on record, covering ¥4.9B ($31.6M) in total reported value, spanning 2021-03-22 to 2025-06-30.
Where does StockDrifts get Star Mica Holdings Co., Ltd. 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 Star Mica Holdings Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.