Seyfert Ltd. (9213) has 20 disclosed large-shareholding filings and 5 disclosed disposals on record, filed by 5 distinct investors. Together those filings cover ¥440M ($2.8M) in reported transaction value. The earliest filing StockDrifts holds for Seyfert Ltd. is dated 2022-02-14; the most recent is 2026-04-06. Across these filings the average return since disclosure is +0.54%, measured from each filing date to the latest available close.
| Date | Type | Source | Insider | Purpose | Shares | Price at filing | Return | Value |
|---|---|---|---|---|---|---|---|---|
| 2026-09-11 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 256.3K | ¥1,052 | -1.4% | ¥25M ($159K) |
| 2026-09-11 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 256.3K | ¥1,052 | - | - |
| 2026-04-06 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 256.3K | ¥907 | +14.3% | ¥21M ($137K) |
| 2026-04-06 | BUY | unknown | 株式会社アーム ARM INC | activist | 256.3K | ¥907 | - | ¥21M ($137K) |
| 2026-03-19 | BUY | unknown | 株式会社アーム ARM INC | activist | 232.8K | ¥765 | - | ¥20M ($128K) |
| 2026-03-19 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 232.8K | ¥765 | +35.6% | ¥20M ($128K) |
| 2026-03-09 | BUY | unknown | 株式会社アーム ARM INC | activist | 206.8K | ¥714 | - | ¥10M ($64K) |
| 2026-03-09 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 206.8K | ¥714 | +45.2% | ¥10M ($64K) |
| 2026-03-04 | BUY | unknown | 株式会社アーム ARM INC | activist | 192.8K | ¥675 | - | ¥4M ($28K) |
| 2026-03-04 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 192.8K | ¥675 | +53.6% | ¥4M ($28K) |
| 2026-03-04 | BUY | unknown | 株式会社アーム ARM INC | activist | 192.8K | ¥675 | - | ¥4M ($28K) |
| 2025-12-10 | SELL | unknown | マネックス証券株式会社 Monex, Inc. | other | 20.8K | ¥754 | -37.5% | ¥36M ($229K) |
| 2025-10-14 | SELL | unknown | マネックス証券株式会社 Monex, Inc. | other | 68.0K | ¥908 | -14.2% | ¥23M ($151K) |
| 2025-10-03 | BUY | Market Buy | マネックス証券株式会社 Monex, Inc. | other | 93.8K | ¥1,109 | -6.5% | ¥26M ($169K) |
| 2025-09-24 | SELL | unknown | マネックス証券株式会社 Monex, Inc. | other | 70.1K | ¥1,515 | +31.6% | ¥29M ($188K) |
| 2025-09-22 | SELL | unknown | マネックス証券株式会社 Monex, Inc. | other | 89.4K | ¥1,251 | +17.1% | ¥108M ($694K) |
| 2025-09-17 | BUY | unknown | マネックス証券株式会社 Monex, Inc. | other | 175.4K | ¥1,027 | +1.0% | ¥180M ($1.2M) |
| 2024-11-22 | BUY | Market Buy | 株式会社ビューティガレージ BEAUTY GARAGE INC. | activist | 115.7K | ¥924 | +12.2% | ¥15M ($98K) |
| 2024-10-07 | BUY | Market Buy | 株式会社ビューティガレージ BEAUTY GARAGE INC. | activist | 99.3K | ¥998 | +3.9% | ¥15M ($99K) |
| 2024-06-06 | BUY | Market Buy | 株式会社ビューティガレージ BEAUTY GARAGE INC. | activist | 84.0K | ¥1,072 | - | ¥90M ($581K) |
| 2024-02-27 | BUY | Market Buy | 株式会社ビューティガレージ BEAUTY GARAGE Inc. | activist | 67.3K | ¥1,144 | -9.3% | ¥77M ($497K) |
| 2023-12-22 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 186.3K | ¥1,083 | -4.3% | ¥17M ($111K) |
| 2023-12-22 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 186.3K | ¥1,083 | - | ¥17M ($111K) |
| 2023-12-22 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 186.3K | ¥1,083 | - | ¥17M ($111K) |
| 2023-10-19 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,066 | - | ¥19M ($120K) |
| 2023-10-19 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,066 | - | ¥19M ($120K) |
| 2023-10-19 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,066 | - | ¥19M ($120K) |
| 2023-10-19 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,066 | -2.7% | ¥19M ($120K) |
| 2023-10-18 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 158.9K | ¥1,051 | - | ¥6M ($39K) |
| 2023-10-18 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 158.9K | ¥1,051 | - | ¥6M ($39K) |
| 2023-10-18 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,051 | - | ¥18M ($118K) |
| 2023-10-18 | BUY | Market Buy | 株式会社アーム ARM INC | activist | 170.5K | ¥1,051 | -1.3% | ¥18M ($118K) |
| 2023-09-08 | SELL | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 0 | ¥1,180 | +12.1% | ¥151M ($972K) |
| 2023-08-03 | BUY | Market Buy | 株式会社アーム ARM INC | passive | 153.1K | ¥1,005 | - | ¥45M ($289K) |
| 2023-08-03 | BUY | Market Buy | 株式会社アーム ARM INC | passive | 153.1K | ¥1,005 | - | ¥45M ($289K) |
| 2023-08-03 | BUY | Market Buy | 株式会社アーム ARM INC | passive | 153.1K | ¥1,005 | +3.2% | ¥45M ($289K) |
| 2023-05-16 | BUY | Market Buy | 株式会社アーム ARM INC | passive | 108.5K | ¥1,007 | - | ¥18M ($115K) |
| 2023-05-16 | BUY | Market Buy | 株式会社アーム ARM INC | passive | 108.5K | ¥1,007 | +3.0% | ¥18M ($115K) |
| 2023-04-10 | BUY | Market Buy | 株式会社アーム Arm inc | passive | 90.7K | ¥1,150 | - | ¥104M ($673K) |
| 2023-04-10 | BUY | Market Buy | 株式会社アーム Arm inc | passive | 90.7K | ¥1,150 | -9.8% | ¥104M ($673K) |
| 2022-11-22 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 127.7K | ¥1,167 | -11.1% | ¥18M ($117K) |
| 2022-09-30 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 112.2K | ¥1,023 | - | ¥24M ($153K) |
| 2022-09-30 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 112.2K | ¥1,023 | +1.4% | ¥24M ($153K) |
| 2022-08-22 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 89.0K | ¥1,093 | - | ¥25M ($159K) |
| 2022-08-22 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 89.0K | ¥1,093 | -5.1% | ¥25M ($159K) |
| 2022-08-22 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 66.5K | ¥1,093 | - | ¥73M ($469K) |
| 2022-08-22 | BUY | Market Buy | 株式会社IBJ IBJ,Inc. | passive | 66.5K | ¥1,093 | -5.1% | ¥73M ($469K) |
| 2022-02-14 | BUY | unknown | 株式会社ビューティープロスペリティ― BeautyProsperity Ltd. | strategic | 308.0K | ¥1,167 | -11.1% | ¥359M ($2.3M) |
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.