Mountain Lake Acquisition Corp.
Mountain Lake Acquisition Corp. (MLAC) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · MLAC · as of Sep 30, 2025
Ownership Breakdown
47
Institutional Holders
▲ 3 vs Q2
$231.24M
Total Inst. Value
▲ $7.33M vs Q2
30.99M
Shares Outstanding
freeFloat 98.07%
22.44M
13F Shares Held
▲ 616,853 vs Q2
Institutional ownership = 13F shares ÷ total outstanding. Insider % = 100 − free float. Public % = free float − institution %. Data: FMP /symbol-positions-summary + /shares-float + SEC EDGAR.
Top Institutional Holders
MLAC largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
MAGNETAR FINANCIAL LLC blank checks | 1.90M | 6.13% | 6.13% | $19.62B | Nov 13, 2025 | — held |
WOLVERINE ASSET MANAGEMENT LLC blank checks | 1.64M | 5.30% | 5.30% | $16.92B | Oct 28, 2025 | ▲ 89.3K |
AQR ARBITRAGE LLC blank checks | 1.50M | 4.84% | 4.84% | $15.45B | Nov 14, 2025 | ▼ 8.0K |
POLAR ASSET MANAGEMENT PARTNERS INC. blank checks | 1.48M | 4.78% | 4.78% | $15.24B | Dec 1, 2025 | — held |
WESTCHESTER CAPITAL MANAGEMENT, LLC blank checks | 1.18M | 3.81% | 3.81% | $12.18B | Nov 14, 2025 | — held |
D. E. SHAW & CO., INC. blank checks | 1.09M | 3.52% | 3.52% | $11.25B | Nov 14, 2025 | — held |
FIRST TRUST CAPITAL MANAGEMENT L.P. blank checks | 1.00M | 3.24% | 3.24% | $10.35B | Nov 17, 2025 | — held |
ALBERTA INVESTMENT MANAGEMENT CORP blank checks | 980.0K | 3.16% | 3.16% | $10.09B | Feb 17, 2026 | — held |
LINDEN ADVISORS LP blank checks | 875.0K | 2.82% | 2.82% | $9.03B | Nov 14, 2025 | — held |
TWO SIGMA INVESTMENTS, LP blank checks | 761.3K | 2.46% | 2.46% | $7.84B | Nov 14, 2025 | — held |
Data from SEC Form 13F filings. Ownership bar normalised to largest holder. Change flags: isNew / isSoldOut / changeInSharesNumber (FMP extract-analytics/holder).
Institutional Activity
Q3 2025 vs prior quarter
Q3 2025
5
Increased
+194.1K shares4
New Positions
first time holders10
Decreased
−267.1K shares1
Sold Out
fully exitedNet shares change (top 50)
73.1K
+194.1K / −267.1K
Net new holders
-2
4 new / 1 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
MLAC insider trading · insider activity
Source: SEC Form 4
Insiders have been net buyers of shares recently. Selling may be driven by pre-scheduled Rule 10b5-1 plans rather than negative sentiment.
12
Buy transactions
4
Sell transactions
3.00
Buy/Sell ratio
$1M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Grinberg Paul Chief Executive Officer | Jun 1, 2026 | J-Other | 478,010 | — | — | 478.0K | Form 4 ↗ |
Vieser Jaime director | Jun 1, 2026 | J-Other | 478,010 | — | — | 478.0K | Form 4 ↗ |
Horlick Douglas CFO and President | Jun 1, 2026 | J-Other | 478,010 | — | — | 478.0K | Form 4 ↗ |
Grinberg Paul Chief Executive Officer | Dec 12, 2024 | Award | 65,968 | — | — | 1.37M | Form 4 ↗ |
Grinberg Paul Chief Executive Officer | Dec 16, 2024 | D-Return | 65,968 | — | — | 1.30M | Form 4 ↗ |
Grinberg Paul Chief Executive Officer | Dec 16, 2024 | Purchase | 12,500 | — | — | 12.5K | Form 4 ↗ |
Grinberg Paul Chief Executive Officer | Dec 16, 2024 | Purchase | 12,500 | — | — | 12.5K | Form 4 ↗ |
Vieser Jaime director | Dec 12, 2024 | Award | 65,242 | — | — | 1.35M | Form 4 ↗ |
Vieser Jaime director | Dec 16, 2024 | D-Return | 65,242 | — | — | 1.29M | Form 4 ↗ |
Vieser Jaime director | Dec 16, 2024 | Purchase | 25,000 | — | — | 25.0K | Form 4 ↗ |
Source: /insider-trading/search (FMP stable). Buy/Sell direction: acquisitionOrDisposition A=Buy, D=Sell. RSU vesting (M-Exempt) excluded from sentiment bar. All data from SEC EDGAR public filings.
About institutional & insider ownership
Mountain Lake Acquisition Corp. (MLAC) is primarily owned by institutional investors, who hold approximately 72.4% of total shares outstanding. Company insiders own approximately 1.93%, while retail and public investors account for the remaining 25.66%.
The largest institutional shareholder of Mountain Lake Acquisition Corp. is MAGNETAR FINANCIAL LLC, holding approximately 1.90 million shares — equal to 6.13% of outstanding shares — as of September 30, 2025.
A total of 47 institutional investors currently hold MLAC stock, with a combined institutional value of approximately $231,237,031 as of the most recent 13F filing period.
Frequently asked questions
MLAC ownershipMountain Lake Acquisition Corp. (MLAC) is primarily owned by institutional investors, who hold approximately 72.4% of shares. The largest shareholder is MAGNETAR FINANCIAL LLC with a 6.13% stake. Company insiders hold 1.93%. Data sourced from SEC Form 13F as of September 30, 2025.