Who has been buying WonderPlanet Inc. stock?

8 distinct investors have filed 11 disclosed large-shareholding filings in WonderPlanet Inc. (4199), most recently on 2026-02-06. 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 WonderPlanet Inc. have?

WonderPlanet Inc. has 11 buy-side and 15 sell-side disclosures on record, covering ¥6.0B ($38.7M) in total reported value, spanning 2021-06-10 to 2026-02-06.

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.

WonderPlanet Inc. 4199

Company

ワンダープラネット株式会社WonderPlanet Inc.

Investors

Buys

Total Value

¥6.0B ($38.7M)

Avg Return

-53.29%

Last Filing

2026-02-06

WonderPlanet Inc. (4199) has 11 disclosed large-shareholding filings and 15 disclosed disposals on record, filed by 8 distinct investors. Together those filings cover ¥6.0B ($38.7M) in reported transaction value. The earliest filing StockDrifts holds for WonderPlanet Inc. is dated 2021-06-10; the most recent is 2026-02-06. Across these filings the average return since disclosure is -53.29%, 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
2026-02-06	SELL	Market Buy	西條晋一 Saijo Shinichi	passive	120.5K	¥1,498	+46.3%	¥85M ($547K)
2025-07-22	BUY	unknown	石川篤 Atsushi Ishikawa	activist	232.0K	¥1,209	-	-
2024-06-19	SELL	unknown	常川友樹 Tomoki Tsunekawa	activist	375.0K	¥1,128	+28.7%	¥8M ($53K)
2024-05-02	SELL	unknown	石川篤 Atsushi Ishikawa	activist	231.7K	¥1,123	+28.4%	¥45M ($293K)
2024-05-02	BUY	unknown	常川友樹 Tomoki Tsunekawa	activist	403.3K	¥1,123	-	¥51M ($331K)
2024-05-02	SELL	unknown	常川友樹 Tomoki Tsunekawa	activist	403.3K	¥1,123	+28.4%	¥51M ($331K)
2023-08-18	SELL	unknown	松井証券株式会社 Matsui Securities Co.,Ltd	other	0	¥1,050	+23.4%	¥136M ($877K)
2023-01-06	BUY	negotiated	Happy Elements株式会社 Happy Elements K.K	strategic	350.0K	¥1,313	-	¥460M ($3.0M)
2023-01-06	BUY	negotiated	Happy Elements株式会社 Happy Elements K.K	strategic	350.0K	¥1,313	-38.8%	¥460M ($3.0M)
2022-11-08	BUY	Market Buy	西條晋一 Saijo Shinichi	passive	150.0K	¥1,581	-49.1%	¥47M ($301K)
2022-10-17	BUY	Market Buy	西條晋一 Saijo Shinichi	passive	150.0K	¥1,138	-29.4%	¥34M ($216K)
2022-09-27	BUY	Market Buy	西條晋一 Saijo Shinichi	passive	120.5K	¥1,223	-34.3%	¥147M ($951K)
2022-08-04	SELL	Market Buy	株式会社海外需要開拓支援機構 Cool Japan Fund Inc	passive	105.8K	¥2,186	+63.2%	¥81M ($524K)
2022-08-03	BUY	unknown	松井証券株式会社 Matsui Securities Co.,Ltd	other	110.1K	¥2,414	-	¥14M ($93K)
2022-08-03	SELL	unknown	松井証券株式会社 Matsui Securities Co.,Ltd	other	111.0K	¥2,414	+66.7%	¥12M ($79K)
2022-07-28	SELL	Market Buy	ユナイテッド株式会社 UNITED, Inc.	passive	110.0K	¥3,500	+77.0%	¥99M ($636K)
2022-07-28	SELL	Market Buy	ユナイテッド株式会社 UNITED, Inc.	passive	138.2K	¥3,500	+77.0%	¥82M ($527K)
2022-05-09	BUY	Market Buy	松井証券株式会社 Matsui Securities Co.,Ltd	other	115.9K	¥1,415	-43.2%	¥8M ($52K)
2022-02-03	BUY	unknown	松井証券株式会社 Matsui Securities Co.,Ltd	other	109.7K	¥1,169	-31.2%	¥128M ($827K)
2022-01-20	BUY	unknown	常川友樹 Tomoki Tsunekawa	activist	375.0K	¥1,236	-	¥541K ($3K)
2022-01-20	SELL	unknown	常川友樹 Tomoki Tsunekawa	activist	375.0K	¥1,236	+35.0%	¥8M ($54K)
2021-09-10	BUY	Market Buy	株式会社海外需要開拓支援機構 Cool Japan Fund Inc	passive	141.7K	¥1,901	-	¥41M ($264K)
2021-09-10	SELL	Market Buy	株式会社海外需要開拓支援機構 Cool Japan Fund Inc	passive	161.0K	¥1,901	+57.7%	¥4M ($27K)
2021-06-25	SELL	Market Buy	グローバル・ブレイン株式会社 Global Brain Corporation	passive	102.7K	¥3,945	+79.6%	¥96M ($618K)
2021-06-22	SELL	Market Buy	株式会社海外需要開拓支援機構 Cool Japan Fund Inc	passive	161.0K	¥3,705	+78.3%	¥198M ($1.3M)
2021-06-21	SELL	Market Buy	グローバル・ブレイン株式会社 Global Brain Corporation	passive	127.0K	¥3,860	+79.2%	¥96M ($621K)
2021-06-18	SELL	Market Buy	ユナイテッド株式会社 UNITED, Inc.	passive	157.8K	¥4,170	+80.7%	¥151M ($977K)
2021-06-17	BUY	unknown	石川篤 Atsushi Ishikawa	activist	225.0K	¥4,680	-82.8%	¥1.1B ($6.8M)
2021-06-17	BUY	unknown	常川友樹 Tomoki Tsunekawa	activist	375.0K	¥4,680	-82.8%	¥1.8B ($11.3M)
2021-06-17	BUY	Market Buy	グローバル・ブレイン株式会社 Global Brain Corporation	passive	152.0K	¥4,680	-82.8%	¥711M ($4.6M)
2021-06-14	BUY	Market Buy	株式会社海外需要開拓支援機構 Cool Japan Fund Inc	passive	214.4K	¥4,815	-83.3%	¥1.0B ($6.7M)
2021-06-10	BUY	Market Buy	ユナイテッド株式会社 UNITED, Inc.	passive	194.0K	¥4,815	-83.3%	¥934M ($6.0M)

Frequently asked questions

Who has been buying WonderPlanet Inc. stock?: 8 distinct investors have filed 11 disclosed large-shareholding filings in WonderPlanet Inc. (4199), most recently on 2026-02-06. 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 WonderPlanet Inc. have?: WonderPlanet Inc. has 11 buy-side and 15 sell-side disclosures on record, covering ¥6.0B ($38.7M) in total reported value, spanning 2021-06-10 to 2026-02-06.
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.