Keystone Acquisition Corp.
KEYYU- Exchange
- Nasdaq
- Industry
- Blank Checks
- SEC CIK
- 0002102771
No open-market purchases or sales by Keystone Acquisition Corp. insiders were filed in the last 90 days; 29 institutions reported holding it in 13F filings for Q2 2026, worth $135.2M in total; no superinvestor holds it.
Holders of 5% or more of KEYYU
Holders whose latest Schedule 13D or 13G filing reports 5% or more of Keystone Acquisition Corp., largest stake first. The change is against the holder's previous filing.
| Holder | Latest form | Stake | Change | First filed | Latest filing | Filing |
|---|---|---|---|---|---|---|
| Magnetar Financial LLC | 13G | 6.96%2.00M shares | New | Aug 13, 20261 filing | Aug 13, 2026 | 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
1 Schedule 13D or 13G filing on Keystone Acquisition Corp., newest first, including old-format filings without a stake.
| Filed (ET) | Filer | Form | Stake | Change | Event date | Filing |
|---|---|---|---|---|---|---|
| Aug 13, 20266:17 AM ET | Magnetar Financial LLCand 3 others | 13G | 6.96%2.00M shares | New | Jun 30, 2026 | SEC |
Form 144: proposed insider sales
Notices from officers, directors and other affiliates planning to sell Keystone Acquisition Corp. shares.
No Form 144 notices for Keystone Acquisition Corp. are on file.