Who has been buying Chugai Mining Co., Ltd. stock?

4 distinct investors have filed 47 disclosed large-shareholding filings in Chugai Mining Co., Ltd. (1491), most recently on 2026-04-22. 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 Chugai Mining Co., Ltd. have?

Chugai Mining Co., Ltd. has 47 buy-side and 24 sell-side disclosures on record, covering ¥20.7B ($133.5M) in total reported value, spanning 2021-06-04 to 2026-04-22.

Where does StockDrifts get Chugai Mining Co., Ltd. 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.

Chugai Mining Co., Ltd. 1491

Company

中外鉱業株式会社Chugai Mining Co., Ltd.

Investors

Buys

Total Value

¥20.7B ($133.5M)

Avg Return

+39.66%

Last Filing

2026-04-22

Chugai Mining Co., Ltd. (1491) has 47 disclosed large-shareholding filings and 24 disclosed disposals on record, filed by 4 distinct investors. Together those filings cover ¥20.7B ($133.5M) in reported transaction value. The earliest filing StockDrifts holds for Chugai Mining Co., Ltd. is dated 2021-06-04; the most recent is 2026-04-22. 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 +39.66%, 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
2026-04-22	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	785.9K	¥948	-21.2%	¥745M ($4.8M)
2026-04-21	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.1M	¥976	-15.5%	¥1.1B ($7.0M)
2026-03-23	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	111.8K	¥962	-0.2%	¥700M ($4.5M)
2026-03-23	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	143.2K	¥962	-0.2%	¥949M ($6.1M)
2026-03-05	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.1M	¥1,089	+11.5%	¥9M ($61K)
2026-02-05	SELL	unknown	株式会社ＳＢＩ証券 SBI SECURITIES Co.,Ltd.	other	1.1M	¥1,069	+9.8%	¥14M ($90K)
2026-01-21	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.2M	¥1,143	+15.7%	¥5M ($32K)
2026-01-08	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.2M	¥1,007	-4.3%	¥13M ($85K)
2025-11-07	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.1M	¥837	+15.2%	¥1M ($8K)
2025-10-21	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.1M	¥940	+2.5%	¥1.1B ($6.9M)
2025-10-21	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	839.5K	¥940	+2.5%	¥789M ($5.1M)
2025-09-22	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	2.1M	¥1,100	-12.4%	¥207.3B ($1.3B)
2025-09-18	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	9.8M	¥1,120	+13.9%	¥14.6B ($94.2M)
2025-08-22	BUY	Market Buy	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.8M	¥1,060	-9.1%	¥61M ($396K)
2025-08-07	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.8M	¥1,300	+25.9%	¥151M ($972K)
2025-07-04	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.9M	¥980	+1.6%	¥369M ($2.4M)
2025-04-22	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	22.9M	¥1,380	-30.1%	¥31.6B ($203.8M)
2025-04-21	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	23.3M	¥1,220	-21.0%	¥28.4B ($183.2M)
2025-03-21	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	1.7M	¥1,480	-34.9%	¥223.0B ($1.4B)
2025-03-17	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	3.0M	¥1,520	+36.6%	¥22.7B ($146.6M)
2025-02-03	SELL	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	62.1K	¥720	-33.9%	¥11.8B ($76.4M)
2024-10-21	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.6M	¥560	+72.1%	¥12.7B ($81.7M)
2024-10-21	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	22.7M	¥560	+72.1%	¥12.7B ($81.8M)
2024-10-21	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	17.9M	¥560	+72.1%	¥10.0B ($64.7M)
2024-10-04	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	964.1K	¥540	+78.5%	¥42.1B ($271.8M)
2024-09-30	SELL	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	10.4M	¥560	-72.1%	¥6.8B ($44.0M)
2024-09-24	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	13.6M	¥560	-72.1%	¥5.0B ($32.0M)
2024-04-19	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	18.4M	¥640	+50.6%	¥11.8B ($75.9M)
2024-04-19	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.4M	¥640	+50.6%	¥14.4B ($92.6M)
2024-04-15	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	22.6M	¥660	+46.1%	¥14.9B ($96.1M)
2024-04-01	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	249.1K	¥640	+50.6%	¥27M ($171K)
2024-03-22	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	2.5M	¥640	+50.6%	¥1.5B ($9.6M)
2024-03-19	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	5.3M	¥640	-50.6%	¥7.7B ($49.5M)
2023-10-19	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.8M	¥620	+55.5%	¥14.1B ($91.3M)
2023-10-16	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	21.9M	¥600	+60.7%	¥13.2B ($84.9M)
2023-10-16	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	17.3M	¥600	+60.7%	¥10.4B ($66.9M)
2023-10-10	SELL	unknown	有限会社マイネン meinen Co.,Ltd	other	18.2M	¥600	-60.7%	¥6.0B ($39.0M)
2023-10-02	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	388.0K	¥620	+55.5%	¥99M ($639K)
2023-09-22	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	3.1M	¥620	-55.5%	¥12.4B ($79.7M)
2023-09-19	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	5.3M	¥620	-55.5%	¥7.5B ($48.4M)
2023-05-09	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	23.0M	¥660	+46.1%	¥15.2B ($98.1M)
2023-04-18	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	17.4M	¥640	+50.6%	¥11.1B ($71.6M)
2023-04-17	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	21.7M	¥640	+50.6%	¥13.9B ($89.6M)
2023-03-22	SELL	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	12.6M	¥640	-50.6%	¥6.4B ($41.4M)
2023-03-20	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	629.9K	¥640	+50.6%	¥269M ($1.7M)
2023-03-17	SELL	unknown	楽天証券株式会社 Rakuten Securities Inc	other	5.5M	¥640	-50.6%	¥7.5B ($48.6M)
2023-01-06	SELL	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	21.7M	¥580	-66.2%	¥17M ($108K)
2022-10-20	BUY	unknown	株式会社SBI証券 SBI SECURITIES Co.,Ltd.	other	22.6M	¥560	+72.1%	¥12.7B ($81.7M)
2022-10-19	BUY	unknown	楽天証券株式会社 Rakuten Securities Inc	other	17.2M	¥560	+72.1%	¥9.7B ($62.3M)
2022-10-17	BUY	unknown	auカブコム証券株式会社 Mitsubishi UFJ Financial Group Inc.	other	21.8M	¥560	+72.1%	¥12.2B ($78.6M)

Showing the 50 most recent of 71 filings.

Frequently asked questions

Who has been buying Chugai Mining Co., Ltd. stock?: 4 distinct investors have filed 47 disclosed large-shareholding filings in Chugai Mining Co., Ltd. (1491), most recently on 2026-04-22. 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 Chugai Mining Co., Ltd. have?: Chugai Mining Co., Ltd. has 47 buy-side and 24 sell-side disclosures on record, covering ¥20.7B ($133.5M) in total reported value, spanning 2021-06-04 to 2026-04-22.
Where does StockDrifts get Chugai Mining Co., Ltd. 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 Chugai Mining Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.