Perimeter Acquisition Corp. I
PMTR- Exchange
- Nasdaq
- Industry
- Blank Checks
- SEC CIK
- 0002061473
No open-market purchases or sales by Perimeter Acquisition Corp. I insiders were filed in the last 90 days; 56 institutions reported holding it in 13F filings for Q2 2026, worth $230.4M in total; no superinvestor holds it.
Holders of 5% or more of PMTR
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Perimeter Acquisition Corp. I, largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Harraden Circle Investments, LLC | 13G/A | 9.28%2.30M shares | – | Feb 13, 20261 filing | Feb 13, 2026 | SEC |
| Alberta Investment Management Corp | 13G | 6.10%1.50M shares | New | May 19, 20251 filing | May 19, 2025 | SEC |
| Magnetar Financial LLC | 13G | 6.05%1.50M shares | New | Aug 8, 20251 filing | Aug 8, 2025 | SEC |
Stakes are as of each holder's latest filing. Holders whose last filing was in the old format (before December 18, 2024) have no stake on record and are not listed, and after an acquisition or delisting holders usually stop filing.
13D and 13G filings
6 Schedule 13D and 13G filings on Perimeter Acquisition Corp. I, newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Feb 13, 20266:00 PM ET | Harraden Circle Investments, LLCand 7 others | 13G/A | 9.28%2.30M shares | – | Dec 31, 2025 | SEC |
| Feb 13, 20264:00 PM ET | Healthcare of Ontario Pension Plan Trust Fund | 13G/A | 1.80%450.0K shares | −3.20 ppfrom 5.00%Below 5% | Dec 31, 2025 | SEC |
| Nov 13, 20255:00 PM ET | Healthcare of Ontario Pension Plan Trust Fund | 13G/A | 5.00%1.25M shares | −1.10 ppfrom 6.10% | Sep 30, 2025 | SEC |
| Aug 13, 20254:02 PM ET | Healthcare of Ontario Pension Plan Trust Fund | 13G | 6.10%1.50M shares | New | Jun 30, 2025 | SEC |
| Aug 8, 20258:54 AM ET | Magnetar Financial LLCand 3 others | 13G | 6.05%1.50M shares | New | Jun 30, 2025 | SEC |
| May 19, 20255:05 PM ET | Alberta Investment Management Corp | 13G | 6.10%1.50M shares | New | May 12, 2025 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Perimeter Acquisition Corp. I shares.
No Form 144 notices for Perimeter Acquisition Corp. I are on file.