Who has been buying Premium Water Holdings,Inc. stock?

9 distinct investors have filed 10 disclosed large-shareholding filings in Premium Water Holdings,Inc. (2588), most recently on 2026-05-13. 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 Premium Water Holdings,Inc. have?

Premium Water Holdings,Inc. has 10 buy-side and 19 sell-side disclosures on record, covering ¥118.7B ($765.7M) in total reported value, spanning 2021-03-23 to 2026-05-13.

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.

Premium Water Holdings,Inc. 2588

Company

株式会社プレミアムウオーターホールディングスPremium Water Holdings,Inc.

Investors

Buys

Total Value

¥118.7B ($765.7M)

Avg Return

+16.55%

Last Filing

2026-05-13

Premium Water Holdings,Inc. (2588) has 10 disclosed large-shareholding filings and 19 disclosed disposals on record, filed by 9 distinct investors. Together those filings cover ¥118.7B ($765.7M) in reported transaction value. The earliest filing StockDrifts holds for Premium Water Holdings,Inc. is dated 2021-03-23; the most recent is 2026-05-13. Across these filings the average return since disclosure is +16.55%, 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
2026-05-13	BUY	private	株式会社光通信	passive	9.0M	¥3,545	+3.0%	¥7.3B ($46.8M)
2026-05-13	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,545	+3.0%	¥9.9B ($63.9M)
2026-05-13	BUY	Market Buy	株式会社W	passive	83.0K	¥3,545	-	¥294M ($1.9M)
2026-03-13	SELL	private	株式会社光通信	passive	9.0M	¥3,975	+8.2%	¥10.6B ($68.4M)
2026-03-13	SELL	private	株式会社HCMAアルファ	passive	12.4M	¥3,975	+8.2%	¥14.5B ($93.5M)
2026-03-02	SELL	private	株式会社光通信	passive	9.0M	¥4,075	+10.4%	¥1.0B ($6.6M)
2026-03-02	SELL	private	株式会社HCMAアルファ	passive	12.4M	¥4,075	+10.4%	¥1.4B ($9.0M)
2025-12-19	BUY	Market Buy	株式会社光通信	passive	9.0M	¥3,185	-	-
2025-12-19	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,185	+14.6%	¥1.0B ($6.6M)
2025-12-01	SELL	Market Buy	株式会社光通信	passive	9.0M	¥3,380	-8.0%	¥2.2B ($14.1M)
2025-12-01	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,380	+8.0%	¥1.2B ($7.6M)
2024-02-22	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.4M	¥3,225	-	¥957M ($6.2M)
2024-02-22	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.4M	¥3,225	-13.2%	¥957M ($6.2M)
2023-10-16	BUY	Market Buy	株式会社HCMAアルファ HCMA Alpha, Inc.	passive	11.6M	¥2,846	-	-
2023-10-16	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,846	-	-
2023-09-07	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,769	-	-
2023-09-07	SELL	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,769	-31.8%	¥525M ($3.4M)
2023-09-07	SELL	Market Buy	株式会社総合生活サービス Sogo Seikatsu Service Co., Ltd.	passive	2.0M	¥2,769	-31.8%	¥66M ($424K)
2023-09-07	SELL	Market Buy	株式会社ブロードピーク Broadpeak Co., Ltd.	passive	9.5M	¥2,769	-31.8%	¥312M ($2.0M)
2023-09-07	SELL	Market Buy	株式会社総合生活サービス Sogo Seikatsu Service Co., Ltd.	unknown	0	¥2,769	-31.8%	¥5.6B ($36.0M)
2023-09-07	BUY	Market Buy	株式会社HCMAアルファ HCMA Alpha, Inc.	passive	11.6M	¥2,769	+31.8%	¥5.6B ($36.0M)
2023-09-01	SELL	subscription	マッコーリーバンクリミテッド Macquarie Bank Limited	passive	1.1M	¥2,807	-30.0%	¥1.3B ($8.4M)
2022-11-08	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.7M	¥2,398	-52.2%	¥240M ($1.5M)
2022-08-22	BUY	Market Buy	レオス・キャピタルワークス株式会社 RHEOS CAPITAL WORKS Inc.	passive	2.6M	¥2,637	+38.4%	¥1.2B ($7.5M)
2022-08-22	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	38.6K	¥2,637	-	¥102M ($657K)
2022-01-05	BUY	subscription	マッコーリーバンクリミテッド Macquarie Bank Limited	passive	1.6M	¥2,750	+32.7%	¥40M ($258K)
2021-10-25	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,150	-	¥18M ($118K)
2021-10-25	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,150	-15.9%	¥18M ($118K)
2021-07-30	BUY	subscription	マッコーリーバンクリミテッド Macquarie Bank Limited	passive	1.6M	¥3,320	+9.9%	¥5.2B ($33.8M)
2021-07-30	BUY	Market Buy	株式会社総合生活サービス Sogo Seikatsu Service Co., Ltd.	passive	2.0M	¥3,320	-	-
2021-07-30	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,320	-	-
2021-07-30	BUY	Market Buy	株式会社ブロードピーク Broadpeak Co., Ltd.	passive	9.5M	¥3,320	-	-
2021-07-30	BUY	subscription	Macquarie Corporate Holdings Pty Limited	passive	125.0K	¥3,320	+9.9%	¥415M ($2.7M)
2021-07-29	SELL	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,305	-10.4%	¥624M ($4.0M)
2021-07-29	SELL	Market Buy	株式会社総合生活サービス Sogo Seikatsu Service Co., Ltd.	passive	2.0M	¥3,305	-10.4%	¥134M ($867K)
2021-07-29	SELL	Market Buy	株式会社ブロードピーク Broadpeak Co., Ltd.	passive	9.5M	¥3,305	-10.4%	¥634M ($4.1M)
2021-04-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,290	-	-
2021-04-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,290	-	-
2021-04-02	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,058.052	+19.4%	¥11.7B ($75.2M)
2021-04-02	SELL	Market Buy	株式会社総合生活サービス Sogo Seikatsu Service Co., Ltd.	passive	2.0M	¥3,058.052	-19.4%	¥14.4B ($93.1M)
2021-04-02	SELL	Market Buy	株式会社ブロードピーク Broadpeak Co., Ltd.	passive	9.5M	¥3,058.052	-19.4%	¥2.2B ($14.5M)
2021-03-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,170.15	-	¥1.1B ($7.1M)
2021-03-23	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,170.15	-15.1%	¥1.1B ($7.1M)

Frequently asked questions

Who has been buying Premium Water Holdings,Inc. stock?: 9 distinct investors have filed 10 disclosed large-shareholding filings in Premium Water Holdings,Inc. (2588), most recently on 2026-05-13. 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 Premium Water Holdings,Inc. have?: Premium Water Holdings,Inc. has 10 buy-side and 19 sell-side disclosures on record, covering ¥118.7B ($765.7M) in total reported value, spanning 2021-03-23 to 2026-05-13.
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.