Who has been buying Nac Co., Ltd. stock?

5 distinct investors have filed 9 disclosed large-shareholding filings in Nac Co., Ltd. (9788), most recently on 2026-03-23. 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 Nac Co., Ltd. have?

Nac Co., Ltd. has 9 buy-side and 10 sell-side disclosures on record, covering ¥2.0B ($12.6M) in total reported value, spanning 2022-04-13 to 2026-03-23.

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.

Nac Co., Ltd. 9788

Company

株式会社ナックNac Co., Ltd.

Investors

Buys

Total Value

¥2.0B ($12.6M)

Avg Return

-18.55%

Last Filing

2026-03-23

Nac Co., Ltd. (9788) has 9 disclosed large-shareholding filings and 10 disclosed disposals on record, filed by 5 distinct investors. Together those filings cover ¥2.0B ($12.6M) in reported transaction value. The earliest filing StockDrifts holds for Nac Co., Ltd. is dated 2022-04-13; the most recent is 2026-03-23. Across these filings the average return since disclosure is -18.55%, 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
2026-09-01	BUY	Market Buy	西山文江	strategic	589.4K	¥524	-0.8%	¥12M ($79K)
2026-09-01	SELL	unknown	株式会社キャピタル	strategic	1.7M	¥524	+0.8%	¥909M ($5.9M)
2026-09-01	BUY	Market Buy	西山由之	strategic	452.4K	¥524	-0.8%	¥10M ($63K)
2026-09-01	BUY	Market Buy	西山文江	strategic	589.4K	¥524	-0.8%	¥32M ($206K)
2026-09-01	SELL	unknown	株式会社キャピタル	strategic	1.7M	¥524	+0.8%	¥793M ($5.1M)
2026-09-01	BUY	Market Buy	西山由之	strategic	452.4K	¥524	-0.8%	¥25M ($162K)
2026-09-01	BUY	Market Buy	西山文江	strategic	589.4K	¥524	-0.8%	¥12M ($79K)
2026-09-01	SELL	unknown	株式会社キャピタル	strategic	1.7M	¥524	+0.8%	¥909M ($5.9M)
2026-09-01	BUY	Market Buy	西山由之	strategic	452.4K	¥524	-0.8%	¥10M ($63K)
2026-05-22	SELL	unknown	SMBC日興証券株式会社	other	421.7K	¥502	-3.6%	¥330M ($2.1M)
2026-05-22	BUY	Market Buy	レモンガス株式会社	passive	1.5M	¥502	-	-
2026-03-23	SELL	unknown	SMBC日興証券株式会社	other	1.1M	¥537	+3.2%	¥3M ($16K)
2026-03-23	SELL	unknown	レモンガス株式会社	passive	1.5M	¥537	+3.2%	¥115M ($743K)
2026-03-03	BUY	Market Buy	SMBC日興証券株式会社	other	1.1M	¥534	-2.6%	¥2M ($16K)
2026-03-03	SELL	Market Buy	レモンガス株式会社	passive	1.7M	¥534	+2.6%	¥164M ($1.1M)
2026-01-28	BUY	unknown	SMBC日興証券株式会社	other	1.1M	¥538	-3.4%	¥20M ($129K)
2026-01-28	SELL	unknown	レモンガス株式会社	passive	2.0M	¥538	+3.4%	¥256M ($1.7M)
2025-10-01	BUY	unknown	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	1.0M	¥546	-4.8%	¥18M ($115K)
2025-10-01	SELL	unknown	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	2.5M	¥546	+4.8%	¥115M ($739K)
2025-02-18	BUY	unknown	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	1.0M	¥662	-21.4%	¥130M ($836K)
2025-02-18	BUY	unknown	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	2.7M	¥662	-21.4%	¥1.7B ($11.2M)
2025-02-10	BUY	Market Buy	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	4.0M	¥614	-	-
2025-02-10	BUY	Market Buy	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	812.7K	¥614	-15.3%	¥309M ($2.0M)
2024-07-08	BUY	unknown	SMBC日興証券株式会社 SMBC Nikko Securities Inc.	other	307.0K	¥584	-	¥179M ($1.2M)
2024-07-08	BUY	unknown	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	4.0M	¥584	-11.0%	¥95M ($615K)
2023-05-18	SELL	unknown	西山由之 Yoshiyuki Nishiyama	strategic	226.2K	¥483	-7.7%	¥242M ($1.6M)
2023-05-18	SELL	unknown	西山由之 Yoshiyuki Nishiyama	strategic	226.2K	¥483	-7.7%	¥242M ($1.6M)
2023-05-18	SELL	unknown	株式会社キャピタル Capital Co., Ltd.	strategic	1.8M	¥483	-7.7%	¥242M ($1.6M)
2023-05-18	BUY	unknown	西山文江 Fumie Nishiyama	strategic	294.7K	¥483	-	-
2023-05-18	SELL	unknown	株式会社キャピタル Capital Co., Ltd.	strategic	1.8M	¥483	-7.7%	¥242M ($1.6M)
2023-05-18	BUY	unknown	西山文江 Fumie Nishiyama	strategic	294.7K	¥483	-	-
2022-10-19	BUY	Market Buy	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	2.0M	¥920	-43.5%	¥49M ($317K)
2022-08-26	BUY	unknown	西山由之 Yoshiyuki Nishiyama	strategic	726.2K	¥945	-	-
2022-08-26	BUY	unknown	株式会社キャピタル Capital Co., Ltd.	strategic	2.3M	¥945	-45.0%	¥232M ($1.5M)
2022-08-26	BUY	unknown	西山文江 Fumie Nishiyama	strategic	294.7K	¥945	-	-
2022-04-13	SELL	Market Buy	レモンガス株式会社 Lemon Gas Co., Ltd.	passive	2.0M	¥939	+44.6%	¥548M ($3.5M)

Frequently asked questions

Who has been buying Nac Co., Ltd. stock?: 5 distinct investors have filed 9 disclosed large-shareholding filings in Nac Co., Ltd. (9788), most recently on 2026-03-23. 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 Nac Co., Ltd. have?: Nac Co., Ltd. has 9 buy-side and 10 sell-side disclosures on record, covering ¥2.0B ($12.6M) in total reported value, spanning 2022-04-13 to 2026-03-23.
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.