Who has been buying Sun Corporation stock?

9 distinct investors have filed 11 disclosed large-shareholding filings in Sun Corporation (6736), 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 Sun Corporation have?

Sun Corporation has 11 buy-side and 4 sell-side disclosures on record, covering ¥67.8B ($437.3M) in total reported value, spanning 2021-05-20 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.

Sun Corporation 6736

Company

サン電子株式会社Sun Corporation

Investors

Buys

Total Value

¥67.8B ($437.3M)

Avg Return

+77.88%

Last Filing

2026-05-13

Sun Corporation (6736) has 11 disclosed large-shareholding filings and 4 disclosed disposals on record, filed by 9 distinct investors. Together those filings cover ¥67.8B ($437.3M) in reported transaction value. The earliest filing StockDrifts holds for Sun Corporation is dated 2021-05-20; the most recent is 2026-05-13. Across these filings the average return since disclosure is +77.88%, 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	SELL	unknown	東海エンジニアリング株式会社	strategic	4.3M	¥8,500	-14.0%	¥3.8B ($24.2M)
2026-05-13	SELL	unknown	オアシスマネジメントカンパニーリミテッド(Oasis Management Company Ltd.) Oasis Management Company Ltd.	activist	4.4M	¥8,500	-14.0%	¥694M ($4.5M)
2026-05-13	BUY	Market Buy	内海倫江	unknown	680.0K	¥8,500	+14.0%	¥5.8B ($37.3M)
2026-05-13	SELL	unknown	東海エンジニアリング株式会社	strategic	4.3M	¥8,500	-14.0%	¥3.8B ($24.2M)
2026-05-13	BUY	unknown	内海倫江	strategic	680.0K	¥8,500	-	¥5.8B ($37.3M)
2026-05-13	SELL	unknown	前田錫枝	strategic	298.4K	¥8,500	-14.0%	¥265M ($1.7M)
2026-05-13	SELL	unknown	前田錫枝	unknown	298.4K	¥8,500	-14.0%	¥265M ($1.7M)
2026-05-08	BUY	Market Buy	バリューアクト・キャピタル・マネジメント・エルピー ValueAct Capital Management, L.P.	activist	0	¥8,660	-	-
2026-05-08	BUY	Market Buy	バリューアクト・ジャパン・マスター・ファンド・エルピー ValueAct Japan Master Fund, L.P.	activist	2.9M	¥8,660	+11.9%	¥4.6B ($29.4M)
2026-04-22	BUY	Market Buy	ヘバラ・ホールドコ・ツー・エル・ピー(Hebara Holdco II, L.P.) Hebara Holdco II, L.P.	activist	4.2M	¥8,290	-	-
2026-04-16	BUY	Market Buy	バリューアクト・キャピタル・マネジメント・エルピー(ValueAct Capital Management	activist	0	¥7,860	-	-
2026-04-16	BUY	Market Buy	バリューアクト・ジャパン・マスター・ファンド・エルピー(ValueAct Japan Master Fund	activist	2.4M	¥7,860	+23.3%	¥3.8B ($24.6M)
2025-10-09	BUY	acquisition	バリューアクト・キャピタル・マネジメント・エルピー(ValueAct Capital Management ValueAct Capital Management	activist	0	¥9,640	+0.5%	-
2025-10-09	BUY	acquisition	バリューアクト・ジャパン・マスター・ファンド・エルピー(ValueAct Japan Master Fund ValueAct Japan Master Fund LP	activist	1.9M	¥9,640	+0.5%	¥18.2B ($117.5M)
2024-08-22	BUY	acquisition	ヘバラ・ホールドコ・ツー・エル・ピー(Hebara Holdco II, L.P.) Hebara Holdco II, L.P.	activist	4.2M	¥6,830	+41.9%	¥29.0B ($186.8M)
2024-03-26	BUY	Market Buy	オアシスマネジメントカンパニーリミテッド(Oasis Management Company Ltd.) Oasis Management Company Ltd.	activist	4.5M	¥3,310	+192.8%	¥2.1B ($13.5M)
2021-10-21	BUY	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	345.2K	¥2,828	+242.6%	¥940M ($6.1M)
2021-10-21	BUY	unknown	UBS証券株式会社 UBS Securities Co., Ltd.	other	25.7K	¥2,828	+242.6%	¥75M ($481K)
2021-10-06	BUY	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	1.3M	¥2,611	+271.1%	¥3.4B ($22.2M)
2021-09-06	SELL	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	389.7K	¥3,375	-187.1%	¥3.1B ($20.3M)
2021-05-20	BUY	unknown	ユービーエス・エイ・ジー(銀行) UBS AG	other	1.3M	¥3,315	+192.3%	¥4.4B ($28.2M)

Frequently asked questions

Who has been buying Sun Corporation stock?: 9 distinct investors have filed 11 disclosed large-shareholding filings in Sun Corporation (6736), 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 Sun Corporation have?: Sun Corporation has 11 buy-side and 4 sell-side disclosures on record, covering ¥67.8B ($437.3M) in total reported value, spanning 2021-05-20 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.