Who owns GP-Act III Acquisition Corp.?
Prices and market caps: Cboe delayed data, at least 15 minutes delayed. Not real-time. Fundamentals from company filings.
Institutional ownership of GPAT from SEC Form 13F filings across 24 reporting managers. All positions are from one synchronized reporting period — 2026-06-30 books, filed up to 45 days after quarter end — so every row is comparable.
As of the 2026-06-30 reporting period, 24 institutions disclosed 8.3M shares of GP-Act III Acquisition Corp. worth $90.8M — about 36.5% of shares outstanding; the largest disclosed holder is Polar Asset Management Partners Inc.. Source: SEC Form 13F filings, parsed by EvidInvest.
24
13F holders
$90.8M
value, 2026 filers
36.5%
of shares outstanding (8.3M sh)
2
new positions (2026 filers)
Top institutional holders
ordered by shares owned · positions as of 2026-06-30 · % of fund = share of the manager's own book · % of co. = share of GPAT's shares outstanding
| # | Manager | Shares | Value | % of fund | % of co. | Δ shares QoQ |
|---|---|---|---|---|---|---|
| 1 | Polar Asset Management Partners Inc. | 1.8M | $19.6M | 0.3% | 7.9% | +53.2% |
| 2 | AQR Arbitrage LLC | 1.4M | $15.2M | 0.2% | 6.1% | -11.2% |
| 3 | MMCAP International Inc. SPC | 1.3M | $13.9M | 1.2% | 5.6% | 0.0% |
| 4 | Alberta Investment Management Corp | 1.0M | $10.9M | 0.1% | 4.4% | -38.5% |
| 5 | BERKLEY W R CORP | 497,064 | $5.4M | 0.3% | 2.2% | -41.3% |
| 6 | HGC Investment Management Inc. | 399,387 | $4.3M | 0.9% | 1.7% | — |
| 7 | Verition Fund Management LLC | 398,885 | $4.3M | 0.0% | 1.7% | +75.3% |
| 8 | TORONTO DOMINION BANK | 345,181 | $3.8M | 0.0% | 1.5% | -45.7% |
| 9 | DEUTSCHE BANK AG\ | 290,000 | $3.1M | 0.0% | 1.3% | 0.0% |
| 10 | PICTON MAHONEY ASSET MANAGEMENT | 250,000 | $2.7M | 0.0% | 1.1% | -81.8% |
| 11 | Periscope Capital Inc. | 150,000 | $1.7M | 0.1% | 0.7% | -40.0% |
| 12 | HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUNDNEW | 149,950 | $1.6M | 0.0% | 0.7% | new |
| 13 | JPMORGAN CHASE & CO | 99,860 | $1.1M | 0.0% | 0.4% | -81.8% |
| 14 | Lineage Point Capital LP | 64,795 | $715,985 | 0.1% | 0.3% | -0.3% |
| 15 | MIZUHO SECURITIES USA LLC | 60,098 | $649,058 | 0.0% | 0.3% | 0.0% |
| 16 | MOORE CAPITAL MANAGEMENT, LP | 50,000 | $543,500 | 0.0% | 0.2% | -75.0% |
| 17 | Kepos Capital LP | 42,500 | $470,000 | 0.6% | 0.2% | 0.0% |
| 18 | GEODE CAPITAL MANAGEMENT, LLC | 21,362 | $232,632 | 0.0% | 0.1% | +87.5% |
| 19 | CITADEL ADVISORS LLC | 20,039 | $218,225 | 0.0% | 0.1% | +16.7% |
| 20 | HRT FINANCIAL LPNEW | 14,965 | $162,000 | 0.0% | 0.1% | new |
| 21 | Clear Street Group Inc. | 9,195 | $99,950 | 0.0% | 0% | -10.9% |
| 22 | LONGFELLOW INVESTMENT MANAGEMENT CO LLC | 7,800 | $84,786 | 0.0% | 0% | 0.0% |
| 23 | MORGAN STANLEY | 23 | $250 | 0.0% | 0% | -64.1% |
| 24 | UBS Group AG | 18 | $195 | 0.0% | 0% | -90.3% |
Source: SEC Form 13F-HR filings (institutional managers over $100M in US-listed positions). 13Fs disclose long positions only, up to 45 days after quarter end; each manager's latest filed quarter is shown per row and dollar values are the manager's filed marks. Aggregates labeled "2026 filers" count only managers whose latest book is a 2026 quarter. Related: valuation · options positioning · supply chain. Research, not investment advice.