Who has been buying Sankyo Kasei Corporation stock?

3 distinct investors have filed 10 disclosed large-shareholding filings in Sankyo Kasei Corporation (8138), most recently on 2025-08-21. 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 Sankyo Kasei Corporation have?

Sankyo Kasei Corporation has 10 buy-side and 2 sell-side disclosures on record, covering ¥388M ($2.5M) in total reported value, spanning 2021-06-18 to 2025-08-21.

Where does StockDrifts get Sankyo Kasei Corporation 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.

Sankyo Kasei Corporation 8138

Company

三京化成株式会社Sankyo Kasei Corporation

Investors

Buys

Total Value

¥388M ($2.5M)

Avg Return

+34.10%

Last Filing

2025-08-21

Sankyo Kasei Corporation (8138) has 10 disclosed large-shareholding filings and 2 disclosed disposals on record, filed by 3 distinct investors. Together those filings cover ¥388M ($2.5M) in reported transaction value. The earliest filing StockDrifts holds for Sankyo Kasei Corporation is dated 2021-06-18; the most recent is 2025-08-21. 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 +34.10%, 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
2025-08-21	BUY	unknown	有限会社新光企画代表取締役小川三香子 Shinko Kikaku Co., Ltd.	strategic	157.6K	¥3,925	+15.9%	¥208M ($1.3M)
2025-08-21	BUY	Market Buy	有限会社新光企画 Shinko Kikaku Co., Ltd.	other	157.6K	¥3,925	+15.9%	¥208M ($1.3M)
2025-02-21	SELL	unknown	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	unknown	0	¥3,275	-38.9%	¥395M ($2.6M)
2025-02-14	SELL	unknown	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	activist	0	¥3,485	-30.6%	¥1.0B ($6.8M)
2024-11-22	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	120.8K	¥4,260	+6.8%	¥74M ($480K)
2024-11-08	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	103.3K	¥4,000	+13.8%	¥47M ($302K)
2024-09-20	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	91.6K	¥3,815	+19.3%	¥44M ($284K)
2024-03-15	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	80.0K	¥3,165	+43.8%	¥253M ($1.6M)
2024-03-12	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	79.2K	¥3,160	+44.0%	¥250M ($1.6M)
2024-03-12	BUY	Market Buy	スイスアジア・フィナンシャル・サービシズ・ピーティーイー・エルティーディー(Swiss-Asia Financial Services Pte. Ltd.) Swiss-Asia Financial Services Pte. Ltd.	passive	79.2K	¥3,160	+44.0%	¥250M ($1.6M)
2022-03-24	BUY	Market Buy	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	activist	301.0K	¥3,110	+46.3%	¥106M ($685K)
2021-12-23	BUY	Market Buy	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	activist	266.8K	¥3,100	+46.8%	¥8M ($53K)
2021-09-17	BUY	Market Buy	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	passive	264.1K	¥3,050	+49.2%	¥88M ($568K)
2021-09-17	BUY	Market Buy	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	passive	264.1K	¥3,050	+49.2%	¥88M ($568K)
2021-06-18	BUY	Market Buy	ブラッククローバーリミテッド(Black Clover Limited) Black Clover Limited	passive	235.3K	¥2,930	+55.3%	¥81M ($522K)

Frequently asked questions

Who has been buying Sankyo Kasei Corporation stock?: 3 distinct investors have filed 10 disclosed large-shareholding filings in Sankyo Kasei Corporation (8138), most recently on 2025-08-21. 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 Sankyo Kasei Corporation have?: Sankyo Kasei Corporation has 10 buy-side and 2 sell-side disclosures on record, covering ¥388M ($2.5M) in total reported value, spanning 2021-06-18 to 2025-08-21.
Where does StockDrifts get Sankyo Kasei Corporation 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 Sankyo Kasei Corporation. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.