Who has been buying West Holdings Corporation stock?

8 distinct investors have filed 21 disclosed large-shareholding filings in West Holdings Corporation (1407), most recently on 2026-01-09. 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 West Holdings Corporation have?

West Holdings Corporation has 21 buy-side and 16 sell-side disclosures on record, covering ¥305.8B ($2.0B) in total reported value, spanning 2021-04-06 to 2026-01-09.

Where does StockDrifts get West Holdings 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.

West Holdings Corporation 1407

Company

株式会社ウエストホールディングスWest Holdings Corporation

Investors

Buys

Total Value

¥305.8B ($2.0B)

Avg Return

-19.87%

Last Filing

2026-01-09

West Holdings Corporation (1407) has 21 disclosed large-shareholding filings and 16 disclosed disposals on record, filed by 8 distinct investors. Together those filings cover ¥305.8B ($2.0B) in reported transaction value. The earliest filing StockDrifts holds for West Holdings Corporation is dated 2021-04-06; the most recent is 2026-01-09. 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 -19.87%, 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
2026-01-09	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.5M	¥1,515	-50.4%	¥774M ($5.0M)
2025-11-10	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.0M	¥1,518	-50.1%	¥1.1B ($7.3M)
2025-10-22	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.7M	¥1,628	-40.0%	¥929M ($6.0M)
2025-10-07	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	4.3M	¥1,825	+24.9%	¥974M ($6.3M)
2025-06-06	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.8M	¥1,488	+53.2%	¥753M ($4.9M)
2025-04-07	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.3M	¥1,365	+67.0%	¥836M ($5.4M)
2025-02-07	SELL	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	2.3K	¥1,595	-42.9%	¥661M ($4.3M)
2025-02-07	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.7M	¥1,595	+42.9%	¥822M ($5.3M)
2024-11-08	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	414.7K	¥2,052	-11.1%	¥132M ($853K)
2024-11-08	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.1M	¥2,052	-11.1%	¥1.3B ($8.3M)
2024-09-06	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.8M	¥2,588	-11.9%	¥762M ($4.9M)
2024-09-06	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	477.5K	¥2,588	-11.9%	¥893M ($5.8M)
2024-08-07	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	135.4K	¥2,157	-5.7%	¥586M ($3.8M)
2024-08-07	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.5M	¥2,157	+5.7%	¥5.3B ($34.0M)
2023-09-25	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	3.5M	¥3,220	-29.2%	¥1.8B ($11.6M)
2023-09-25	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	405.4K	¥3,220	-29.2%	¥563M ($3.6M)
2023-07-24	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	228.3K	¥2,813	-19.0%	¥39M ($251K)
2023-07-24	SELL	Market Buy	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	1.0K	¥2,813	+19.0%	¥375M ($2.4M)
2023-07-24	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.9M	¥2,813	-19.0%	¥1.3B ($8.6M)
2023-06-26	BUY	unknown	吉川恵子 Keiko Yoshikawa	activist	203.4K	¥2,594	-12.1%	¥528M ($3.4M)
2023-06-26	BUY	unknown	吉川恵子 Keiko Yoshikawa	activist	203.4K	¥2,594	-12.1%	¥528M ($3.4M)
2023-06-26	SELL	unknown	吉川隆 Takashi Kikkawa	activist	17.4M	¥2,594	+12.1%	¥251M ($1.6M)
2023-06-26	SELL	unknown	吉川隆 Takashi Kikkawa	activist	17.4M	¥2,594	+12.1%	¥251M ($1.6M)
2022-09-07	BUY	Market Buy	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	218.1K	¥4,450	-48.8%	¥184M ($1.2M)
2022-09-07	BUY	Market Buy	みずほ証券株式会社 Mizuho Securities Co., Ltd.	other	134.7K	¥4,450	-48.8%	¥599M ($3.9M)
2022-09-07	BUY	Market Buy	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.4M	¥4,450	-48.8%	¥1.3B ($8.2M)
2022-05-02	BUY	unknown	吉川恵子 Keiko Yoshikawa	activist	203.4K	¥5,390	-57.7%	¥1.1B ($7.1M)
2022-05-02	BUY	unknown	吉川隆 Takashi Kikkawa	activist	17.5M	¥5,390	-57.7%	¥93.1B ($600.9M)
2022-04-28	SELL	unknown	吉川恵子 Keiko Yoshikawa	activist	203.4K	¥5,220	+56.3%	¥721M ($4.7M)
2022-04-28	SELL	unknown	吉川恵子 Keiko Yoshikawa	activist	203.4K	¥5,220	+56.3%	¥721M ($4.7M)
2022-04-28	BUY	unknown	吉川隆 Takashi Kikkawa	activist	18.4M	¥5,220	-56.3%	¥95.0B ($613.1M)
2022-04-28	BUY	unknown	吉川隆 Takashi Kikkawa	activist	18.4M	¥5,220	-56.3%	¥95.0B ($613.1M)
2022-04-07	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	177.0K	¥4,995	-54.4%	¥884M ($5.7M)
2022-04-07	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.2M	¥4,995	-54.4%	¥10.8B ($69.4M)
2021-09-24	SELL	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	166.3K	¥5,610	+59.4%	¥310M ($2.0M)
2021-09-24	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	1.6M	¥5,610	-59.4%	¥8.8B ($57.0M)
2021-08-05	SELL	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	2.1M	¥4,860	+53.1%	¥2.5B ($15.9M)
2021-05-12	BUY	unknown	アセットマネジメントOneインターナショナル Asset Management One International Ltd.	other	221.4K	¥3,130	-27.2%	¥693M ($4.5M)
2021-05-12	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	2.1M	¥3,130	-27.2%	¥6.6B ($42.6M)
2021-04-06	SELL	unknown	インベスコキャピタルマネジメントエルエルシー Invesco Capital Management LLC	other	889.3K	¥3,001.476	+24.1%	¥774M ($5.0M)
2021-04-06	SELL	unknown	インベスコ・アセット・マネジメント株式会社 Invesco Asset Management (Japan) Limited	other	801.5K	¥3,001.476	+24.1%	¥1.3B ($8.4M)

Frequently asked questions

Who has been buying West Holdings Corporation stock?: 8 distinct investors have filed 21 disclosed large-shareholding filings in West Holdings Corporation (1407), most recently on 2026-01-09. 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 West Holdings Corporation have?: West Holdings Corporation has 21 buy-side and 16 sell-side disclosures on record, covering ¥305.8B ($2.0B) in total reported value, spanning 2021-04-06 to 2026-01-09.
Where does StockDrifts get West Holdings 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 West Holdings Corporation. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.