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Rock Field Co., Ltd. 2910

Company
株式会社ロック・フィールドRock Field Co., Ltd.
Investors
4
Buys
3
Total Value
¥6.4B ($41.5M)
Avg Return
-8.53%
Last Filing
2025-06-05

Rock Field Co., Ltd. (2910) has 3 disclosed large-shareholding filings and 3 disclosed disposals on record, filed by 4 distinct investors. Together those filings cover ¥6.4B ($41.5M) in reported transaction value. The earliest filing StockDrifts holds for Rock Field Co., Ltd. is dated 2021-04-05; the most recent is 2025-06-05. 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 -8.53%, measured from each filing date to the latest available close.

Price & insider activity (12 months)

Recent filings

DateTypeSourceInsiderPurposeSharesPrice at filingReturnValue
2025-06-05SELLunknown
ロック・フィールド取引先持株会 理事長 松永 茂生
Matsunaga Shigeo
strategic0¥1,490+8.1%¥2.2B ($13.9M)
2025-06-05BUYunknown
ロック・フィールド取引先持株会 理事長 小澤 拓
Ozawa Taku
strategic1.5M¥1,490-8.1%¥2.2B ($14.3M)
2023-06-02SELLunknown
ロック・フィールド取引先持株会 理事長 小林 俊一郎
Kobayashi Syunichiro
strategic0¥1,456+5.9%¥2.0B ($12.9M)
2023-06-02BUYunknown
ロック・フィールド取引先持株会 理事長 松永 茂生
Matsunaga Shigeo
strategic1.4M¥1,456-5.9%¥2.1B ($13.6M)
2021-04-05SELLunknown
ロック・フィールド取引先持株会 理事長 安倍 寛信
Abe Hironobu
strategic0¥1,550.465+11.6%¥2.1B ($13.4M)
2021-04-05BUYunknown
ロック・フィールド取引先持株会 理事長 小林 俊一郎
Kobayashi Shunichiro
strategic1.4M¥1,550.465-11.6%¥2.1B ($13.7M)

Frequently asked questions

Who has been buying Rock Field Co., Ltd. stock?
4 distinct investors have filed 3 disclosed large-shareholding filings in Rock Field Co., Ltd. (2910), most recently on 2025-06-05. 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 Rock Field Co., Ltd. have?
Rock Field Co., Ltd. has 3 buy-side and 3 sell-side disclosures on record, covering ¥6.4B ($41.5M) in total reported value, spanning 2021-04-05 to 2025-06-05.
Where does StockDrifts get Rock Field 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 Rock Field Co., Ltd.. For how StockDrifts scores these disclosures, see the Japan insider signal tier research, or browse every Japanese stock we track.