Who has been buying Wintest Corp. stock?

3 distinct investors have filed 10 disclosed large-shareholding filings in Wintest Corp. (6721), most recently on 2026-02-27. 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 Wintest Corp. have?

Wintest Corp. has 10 buy-side and 10 sell-side disclosures on record, covering ¥1.8B ($11.7M) in total reported value, spanning 2022-03-04 to 2026-02-27.

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.

Wintest Corp. 6721

Company

ウインテスト株式会社Wintest Corp.

Investors

Buys

Total Value

¥1.8B ($11.7M)

Avg Return

-9.97%

Last Filing

2026-02-27

Wintest Corp. (6721) has 10 disclosed large-shareholding filings and 10 disclosed disposals on record, filed by 3 distinct investors. Together those filings cover ¥1.8B ($11.7M) in reported transaction value. The earliest filing StockDrifts holds for Wintest Corp. is dated 2022-03-04; the most recent is 2026-02-27. Across these filings the average return since disclosure is -9.97%, 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
2026-07-14	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	2.8M	¥83	+7.2%	¥47M ($302K)
2026-07-03	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	3.5M	¥89	+13.5%	¥49M ($317K)
2026-06-24	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	4.1M	¥80	+3.8%	¥95M ($613K)
2026-05-27	BUY	Market Buy	abc株式会社 abc Co., Ltd.	passive	5.5M	¥86	-	¥50M ($325K)
2026-05-27	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	5.3M	¥86	+10.5%	¥67M ($429K)
2026-02-27	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	6.1M	¥126	+38.9%	¥71M ($458K)
2026-02-20	SELL	Market Buy	abc株式会社 abc Co., Ltd.	passive	6.7M	¥123	+37.4%	¥20M ($128K)
2026-02-20	BUY	Market Buy	abc株式会社 abc Co., Ltd.	passive	6.7M	¥123	-	¥20M ($128K)
2026-01-19	BUY	Market Buy	abc株式会社 abc Co., Ltd.	passive	7.0M	¥122	-36.9%	¥854M ($5.5M)
2025-07-24	SELL	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	4.2M	¥131	+41.2%	¥422M ($2.7M)
2025-07-24	SELL	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.2M	¥131	+41.2%	¥131M ($845K)
2025-07-24	SELL	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	1.4M	¥131	+41.2%	¥233M ($1.5M)
2024-12-26	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	8.7M	¥117	-34.2%	¥106M ($682K)
2024-12-26	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	8.8M	¥117	-	¥93M ($603K)
2024-11-25	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	10.0M	¥71	-	¥578M ($3.7M)
2024-11-25	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	10.0M	¥71	+8.4%	¥578M ($3.7M)
2023-10-26	BUY	Market Buy	楽言海外国際(香港)有限公司 Rakugen Overseas International (HK) Limited	passive	3.7M	¥113	-31.9%	¥415M ($2.7M)
2023-04-11	SELL	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	1.8M	¥126	+38.9%	¥51M ($331K)
2023-03-28	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	2.3M	¥125	-	¥55M ($355K)
2023-03-28	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	2.3M	¥125	-38.4%	¥55M ($355K)
2023-03-16	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	2.8M	¥126	-	¥43M ($276K)
2023-03-16	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.2M	¥126	-	¥60M ($387K)
2023-03-16	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	2.8M	¥126	-38.9%	¥43M ($276K)
2023-03-16	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.2M	¥126	-	¥60M ($387K)
2023-03-15	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.7M	¥130	-	¥15M ($94K)
2023-03-15	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.7M	¥130	-	¥15M ($94K)
2023-03-15	BUY	subscription	GFA株式会社 GFA Co., Ltd.	passive	3.9M	¥130	-	¥458M ($3.0M)
2023-03-10	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	2.9M	¥136	-43.4%	¥28M ($180K)
2023-03-10	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.2M	¥136	-	¥89M ($576K)
2023-03-10	BUY	Market Buy	GFA株式会社 GFA Co., Ltd.	passive	3.2M	¥136	-43.4%	¥389M ($2.5M)
2023-03-06	BUY	subscription	GFA株式会社 GFA Co., Ltd.	passive	3.9M	¥135	-	¥475M ($3.1M)
2023-03-06	BUY	subscription	GFA株式会社 GFA Co., Ltd.	passive	3.9M	¥135	-43.0%	¥526M ($3.4M)
2022-11-22	SELL	Market Buy	三田証券株式会社 MITA SECURITIES Co.,Ltd.	passive	1.6M	¥140	+45.0%	¥72M ($465K)
2022-06-07	SELL	Market Buy	三田証券株式会社 MITA SECURITIES Co.,Ltd.	passive	2.1M	¥148	+48.0%	¥68M ($437K)
2022-04-07	SELL	Market Buy	三田証券株式会社 MITA SECURITIES Co.,Ltd.	passive	2.6M	¥148	+48.0%	¥61M ($396K)
2022-03-23	SELL	Market Buy	三田証券株式会社 MITA SECURITIES Co.,Ltd.	passive	3.1M	¥159	+51.6%	¥57M ($368K)
2022-03-04	BUY	Market Buy	三田証券株式会社 MITA SECURITIES Co.,Ltd.	passive	3.4M	¥156	-50.6%	¥538M ($3.5M)

Frequently asked questions

Who has been buying Wintest Corp. stock?: 3 distinct investors have filed 10 disclosed large-shareholding filings in Wintest Corp. (6721), most recently on 2026-02-27. 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 Wintest Corp. have?: Wintest Corp. has 10 buy-side and 10 sell-side disclosures on record, covering ¥1.8B ($11.7M) in total reported value, spanning 2022-03-04 to 2026-02-27.
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.