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.

Where does StockDrifts get Premium Water Holdings,Inc. 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.

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. 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 +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	Market Buy	株式会社W	passive	83.0K	¥3,545	-4.1%	¥294M ($1.9M)
2026-05-13	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,545	-4.1%	¥9.9B ($63.9M)
2026-05-13	BUY	private	株式会社光通信	passive	9.0M	¥3,545	-4.1%	¥7.3B ($46.8M)
2026-03-13	SELL	private	株式会社HCMAアルファ	passive	12.4M	¥3,975	+8.4%	¥45.0B ($290.1M)
2026-03-13	SELL	private	株式会社光通信	passive	9.0M	¥3,975	+8.4%	¥32.9B ($212.4M)
2026-03-02	SELL	private	株式会社HCMAアルファ	passive	12.4M	¥4,075	+10.7%	¥45.0B ($290.1M)
2026-03-02	SELL	private	株式会社光通信	passive	9.0M	¥4,075	+10.7%	¥32.9B ($212.4M)
2025-12-19	BUY	Market Buy	株式会社光通信	passive	9.0M	¥3,185	-14.3%	¥32.9B ($212.4M)
2025-12-19	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,185	+14.3%	¥45.0B ($290.1M)
2025-12-01	BUY	Market Buy	株式会社HCMAアルファ	passive	12.4M	¥3,380	+7.7%	¥45.0B ($290.1M)
2025-12-01	SELL	Market Buy	株式会社光通信	passive	9.0M	¥3,380	-7.7%	¥32.9B ($212.4M)
2024-02-22	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.4M	¥3,225	-12.9%	¥957M ($6.2M)
2024-02-22	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.4M	¥3,225	+12.9%	¥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	+27.9%	¥32.9B ($212.2M)
2023-10-16	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,846	+27.9%	¥28.0B ($180.7M)
2023-09-07	BUY	Market Buy	株式会社HCMAアルファ HCMA Alpha, Inc.	passive	11.6M	¥2,769	+31.5%	¥5.6B ($36.0M)
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	-31.5%	¥5.6B ($36.0M)
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	-31.5%	¥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.	passive	2.0M	¥2,769	-31.5%	¥66M ($424K)
2023-09-07	SELL	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,769	-31.5%	¥525M ($3.4M)
2023-09-07	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥2,769	+31.5%	¥27.2B ($175.8M)
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	-29.7%	¥1.3B ($8.4M)
2022-11-08	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.7M	¥2,398	-51.8%	¥240M ($1.5M)
2022-08-22	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	38.6K	¥2,637	+38.0%	¥102M ($657K)
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	+38.0%	¥1.2B ($7.5M)
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	+32.4%	¥40M ($258K)
2021-10-25	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,150	-15.6%	¥18M ($118K)
2021-10-25	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,150	+15.6%	¥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	+9.6%	¥5.2B ($33.8M)
2021-07-30	BUY	subscription	Macquarie Corporate Holdings Pty Limited	passive	125.0K	¥3,320	+9.6%	¥415M ($2.7M)
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	+9.6%	¥31.4B ($202.7M)
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	+9.6%	¥6.6B ($42.8M)
2021-07-30	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,320	+9.6%	¥32.7B ($210.8M)
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	-10.1%	¥634M ($4.1M)
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	-10.1%	¥134M ($867K)
2021-07-29	SELL	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,305	-10.1%	¥624M ($4.0M)
2021-04-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,290	+10.6%	¥5.8B ($37.3M)
2021-04-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,290	+10.6%	¥5.8B ($37.3M)
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	-19.0%	¥2.2B ($14.5M)
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	-19.0%	¥14.4B ($93.1M)
2021-04-02	BUY	Market Buy	株式会社光通信 HIKARI TSUSHIN, Inc.	passive	9.8M	¥3,058.052	+19.0%	¥11.7B ($75.2M)
2021-03-23	SELL	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,170.15	-14.8%	¥1.1B ($7.1M)
2021-03-23	BUY	unknown	萩尾陽平 YOHEI HAGIO	activist	1.8M	¥3,170.15	+14.8%	¥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.
Where does StockDrifts get Premium Water Holdings,Inc. 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 Premium Water Holdings,Inc.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.