Who has been buying BASE, Inc. stock?

16 distinct investors have filed 45 disclosed large-shareholding filings in BASE, Inc. (4477), most recently on 2026-02-13. 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 BASE, Inc. have?

BASE, Inc. has 45 buy-side and 22 sell-side disclosures on record, covering ¥26.5B ($171.1M) in total reported value, spanning 2021-03-30 to 2026-02-13.

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.

BASE, Inc. 4477

Company

BASE株式会社BASE, Inc.

Investors

Buys

Total Value

¥26.5B ($171.1M)

Avg Return

-52.26%

Last Filing

2026-02-13

BASE, Inc. (4477) has 45 disclosed large-shareholding filings and 22 disclosed disposals on record, filed by 16 distinct investors. Together those filings cover ¥26.5B ($171.1M) in reported transaction value. The earliest filing StockDrifts holds for BASE, Inc. is dated 2021-03-30; the most recent is 2026-02-13. Across these filings the average return since disclosure is -52.26%, 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
2026-09-01	BUY	unknown	牧寛之 Maki Hiroyuki	strategic	24.2M	¥365	-	-
2026-05-19	SELL	unknown	牧寛之 Maki Hiroyuki	activist	24.2M	¥264	-27.6%	¥6M ($40K)
2026-02-13	BUY	unknown	牧寛之 Maki Hiroyuki	other	24.2M	¥314	-	-
2025-10-07	SELL	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	4.4M	¥320	-5.3%	¥494M ($3.2M)
2025-09-05	BUY	unknown	牧寛之 Maki Hiroyuki	other	24.2M	¥361	-	-
2025-08-15	BUY	Market Buy	牧寛之 Maki Hiroyuki	activist	24.2M	¥395	-14.7%	¥2.9B ($18.9M)
2025-08-07	BUY	unknown	アセットマネジメントOne株式会社 Asset Management One Co., Ltd.	other	6.0M	¥379	-11.1%	¥2.3B ($14.6M)
2025-03-12	BUY	Market Buy	牧寛之 Maki Hiroyuki	activist	16.6M	¥524	-35.7%	¥1.7B ($11.1M)
2025-03-11	BUY	Market Buy	牧寛之 Maki Hiroyuki	activist	13.3M	¥510	-33.9%	¥2.0B ($13.1M)
2025-03-10	BUY	Market Buy	牧寛之 Maki Hiroyuki	activist	9.3M	¥454	-25.8%	¥1.4B ($8.9M)
2025-03-07	BUY	unknown	牧寛之 Maki Hiroyuki	activist	6.3M	¥384	-12.2%	¥2.4B ($15.6M)
2025-02-27	SELL	unknown	株式会社丸井グループ MARUI GROUP CO.,LTD.	unknown	0	¥368	+8.4%	¥2.8B ($18.0M)
2024-07-19	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	3.6M	¥266	-26.7%	¥12M ($79K)
2024-07-19	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	2.0M	¥266	-26.7%	¥394M ($2.5M)
2024-06-07	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	3.6M	¥275	-22.6%	¥137M ($882K)
2024-06-07	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	3.4M	¥275	-22.6%	¥223M ($1.4M)
2024-05-16	BUY	Market Buy	鶴岡裕太 Yuta Tsuruoka	activist	20.3M	¥303	+11.2%	¥368M ($2.4M)
2024-02-06	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	4.1M	¥320	-5.3%	¥365M ($2.4M)
2024-02-06	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	4.2M	¥320	-5.3%	¥81M ($523K)
2023-12-21	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	5.3M	¥227	-48.5%	¥235M ($1.5M)
2023-12-21	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	4.5M	¥227	-48.5%	¥112M ($725K)
2023-11-21	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	6.3M	¥262	-28.6%	¥169M ($1.1M)
2023-11-21	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	5.0M	¥262	-28.6%	¥263M ($1.7M)
2023-08-15	SELL	unknown	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	6.9M	¥360	+6.4%	¥222M ($1.4M)
2023-08-15	SELL	unknown	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	5.9M	¥360	+6.4%	¥218M ($1.4M)
2022-12-06	BUY	unknown	モルガン・スタンレーMUFG証券株式会社 Morgan Stanley MUFG Securities Co., Ltd.	other	680.6K	¥295	+14.2%	¥191M ($1.2M)
2022-12-06	BUY	unknown	モルガン・スタンレー・アンド・カンパニー・インターナショナル・ピーエルシー Morgan Stanley & Co. International plc	other	1.4M	¥295	+14.2%	¥46M ($299K)
2022-12-06	SELL	unknown	モルガン・スタンレー・アンド・カンパニー・エルエルシー Morgan Stanley & Co. LLC	other	479.0K	¥295	-14.2%	¥122M ($790K)
2022-11-21	BUY	unknown	モルガン・スタンレーMUFG証券株式会社 Morgan Stanley MUFG Securities Co., Ltd.	other	3.8M	¥301	+12.0%	¥1.1B ($7.3M)
2022-11-21	BUY	unknown	モルガン・スタンレー・アンド・カンパニー・インターナショナル・ピーエルシー Morgan Stanley & Co. International plc	other	1.2M	¥301	+12.0%	¥371M ($2.4M)
2022-11-21	BUY	unknown	モルガン・スタンレー・アンド・カンパニー・エルエルシー Morgan Stanley & Co. LLC	other	896.5K	¥301	+12.0%	¥270M ($1.7M)
2022-04-15	BUY	Market Buy	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	7.3M	¥435	-22.5%	¥442M ($2.9M)
2022-04-15	BUY	Market Buy	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	6.4M	¥435	-22.5%	¥78M ($502K)
2022-03-15	BUY	Market Buy	ベイリー・ギフォード・アンド・カンパニー Baillie Gifford & Co	other	6.3M	¥378	-10.8%	¥421M ($2.7M)
2022-03-15	BUY	Market Buy	ベイリー・ギフォード・オーバーシーズ・リミテッド Baillie Gifford Overseas Limited	other	6.2M	¥378	-10.8%	¥42M ($272K)
2022-03-14	SELL	unknown	タイボーン・キャピタル・マネジメント(香港)リミテッド(Tybourne Capital Management (HK) Limited) Tybourne Capital Management (HK) Limited	other	5.3M	¥365	+7.7%	¥661M ($4.3M)
2022-02-15	SELL	negotiated	鶴岡裕太 Yuta Tsuruoka	activist	18.4M	¥402	+16.2%	¥225M ($1.4M)
2021-12-20	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	3.2M	¥613	-	-
2021-12-20	BUY	Market Buy	JPモルガン・アセット・マネジメント(アジア・パシフィック)リミテッドLimited) JPMorgan Asset Management (Asia Pacific	other	123.3K	¥613	-	-
2021-12-20	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	427.6K	¥613	-45.0%	¥204M ($1.3M)
2021-12-20	SELL	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	868.6K	¥613	+45.0%	¥838M ($5.4M)
2021-12-20	BUY	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・エルエルシー J.P. Morgan Securities LLC	other	213.1K	¥613	-45.0%	¥68M ($440K)
2021-12-03	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	3.2M	¥686	-50.9%	¥2.2B ($14.2M)
2021-12-03	BUY	Market Buy	JPモルガン・アセット・マネジメント(アジア・パシフィック)リミテッドLimited) JPMorgan Asset Management (Asia Pacific	other	123.3K	¥686	-50.9%	¥85M ($546K)
2021-12-03	BUY	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・ピーエルシー J.P. Morgan Securities plc	other	2.2M	¥686	-50.9%	¥1.5B ($9.9M)
2021-12-03	BUY	Market Buy	ジェー・ピー・モルガン・セキュリティーズ・エルエルシー J.P. Morgan Securities LLC	other	102.2K	¥686	-50.9%	¥70M ($452K)
2021-12-03	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	92.7K	¥686	-50.9%	¥64M ($410K)
2021-11-18	BUY	Market Buy	JPモルガン・アセット・マネジメント株式会社 JPMorgan Asset Management (Japan) Limited	passive	3.2M	¥840	-	-
2021-11-18	BUY	Market Buy	JPモルガン・アセット・マネジメント(アジア・パシフィック)リミテッドLimited) JPMorgan Asset Management (Asia Pacific	other	123.3K	¥840	-	-
2021-11-18	BUY	Market Buy	JPモルガン証券株式会社 JPMorgan Securities Japan Co., Ltd.	other	493.6K	¥840	-	¥415M ($2.7M)

Showing the 50 most recent of 80 filings.

Frequently asked questions

Who has been buying BASE, Inc. stock?: 16 distinct investors have filed 45 disclosed large-shareholding filings in BASE, Inc. (4477), most recently on 2026-02-13. 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 BASE, Inc. have?: BASE, Inc. has 45 buy-side and 22 sell-side disclosures on record, covering ¥26.5B ($171.1M) in total reported value, spanning 2021-03-30 to 2026-02-13.
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.