Montauk Renewables, Inc.
Montauk Renewables, Inc. (MNTK) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · MNTK · as of Sep 30, 2025
Ownership Breakdown
88
Institutional Holders
▲ 5 vs Q2
$41.45M
Total Inst. Value
▼ $4.50M vs Q2
142.34M
Shares Outstanding
freeFloat 29.28%
20.62M
13F Shares Held
▼ 72,996 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
MNTK largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
BLACKROCK, INC. gas & other services combined | 4.27M | 2.98% | 2.98% | $8.58B | Nov 12, 2025 | ▼ 109.4K |
VANGUARD GROUP INC gas & other services combined | 3.95M | 2.76% | 2.76% | $7.94B | Nov 7, 2025 | ▼ 23.5K |
GEODE CAPITAL MANAGEMENT, LLC gas & other services combined | 1.69M | 1.18% | 1.18% | $3.39B | Nov 12, 2025 | ▲ 9.8K |
BAADER BANK AKTIENGESELLSCHAFT gas & other services combined | 1.60M | 1.12% | 1.12% | $3.23B | Nov 6, 2025 | — held |
STATE STREET CORP gas & other services combined | 1.39M | 97.41% | 97.41% | $2.80B | Nov 14, 2025 | ▲ 30.7K |
DIMENSIONAL FUND ADVISORS LP gas & other services combined | 976.0K | 68.24% | 68.24% | $1.96B | Nov 12, 2025 | ▼ 6.2K |
AMERICAN CENTURY COMPANIES INC gas & other services combined | 955.1K | 66.77% | 66.77% | $1.92B | Nov 12, 2025 | — held |
CHARLES SCHWAB INVESTMENT MANAGEMENT INC gas & other services combined | 545.0K | 38.10% | 38.10% | $1.10B | Nov 10, 2025 | ▲ 20.9K |
NORTHERN TRUST CORP gas & other services combined | 527.2K | 36.86% | 36.86% | $1.06B | Nov 14, 2025 | ▲ 10.3K |
HOSKING PARTNERS LLP gas & other services combined | 395.9K | 27.68% | 27.68% | $795.86M | Oct 23, 2025 | ▲ 217 |
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
17
Increased
+602.5K shares3
New Positions
first time holders21
Decreased
−530.0K shares0
Sold Out
fully exitedNet shares change (top 50)
+72.5K
+602.5K / −530.0K
Net new holders
-1
3 new / 0 exited
Based on top 50 institutional holders by position size. Fields: isNew, isSoldOut, changeInSharesNumber (FMP extract-analytics/holder, limit=50).
Insider Buying vs Selling
MNTK 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.
5
Buy transactions
0
Sell transactions
0.00
Buy/Sell ratio
$0M
Total disposed
Recent Insider Transactions
Showing 10 most recent · Common Stock only
| Name · Role | Date | Type | Shares | Price | Value | After Trans. | Filing |
|---|---|---|---|---|---|---|---|
Shaw James A Chief Operating Officer | May 20, 2026 | Award | 282,842 | — | — | 477.4K | Form 4 ↗ |
McClain Sean F President & CEO | May 20, 2026 | Award | 383,183 | — | — | 1.14M | Form 4 ↗ |
Van Asdalan Kevin A Chief Financial Officer | May 20, 2026 | Award | 302,982 | — | — | 497.5K | Form 4 ↗ |
Ciroli John Chief Legal Officer | May 20, 2026 | Award | 302,982 | — | — | 470.8K | Form 4 ↗ |
Copelyn John A director | May 11, 2026 | Purchase | 17,506 | $1.45 | $25.4K | 17.5K | Form 4 ↗ |
Frank Sharon R VP Environ Health & Safety | Nov 24, 2025 | Tax Withhold | 2,748 | $1.67 | $4.6K | 39.3K | Form 4 ↗ |
Frank Sharon R VP Environ Health & Safety | Nov 24, 2024 | Tax Withhold | 2,748 | $4.46 | $12.3K | 42.0K | Form 4 ↗ |
Frank Sharon R VP Environ. Health & Safety | Nov 24, 2023 | Tax Withhold | 2,658 | $9.09 | $24.2K | 44.8K | Form 4 ↗ |
Barsch Michael See Remarks | Sep 15, 2023 | Award | 75,000 | $9.57 | $717.8K | 75.0K | Form 4 ↗ |
Van Asdalan Kevin A CFO and Treasurer | Apr 19, 2023 | Award | 166,667 | $6.77 | $1.13M | 166.7K | 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
Montauk Renewables, Inc. (MNTK) is primarily owned by institutional investors, who hold approximately 14.5% of total shares outstanding. Company insiders own approximately 70.72%, while retail and public investors account for the remaining 14.79%.
The largest institutional shareholder of Montauk Renewables, Inc. is BLACKROCK, INC., holding approximately 4.27 million shares — equal to 2.98% of outstanding shares — as of September 30, 2025.
A total of 88 institutional investors currently hold MNTK stock, with a combined institutional value of approximately $41,453,393 as of the most recent 13F filing period.
Frequently asked questions
MNTK ownershipMontauk Renewables, Inc. (MNTK) is primarily owned by institutional investors, who hold approximately 14.5% of shares. The largest shareholder is BLACKROCK, INC. with a 2.98% stake. Company insiders hold 70.72%. Data sourced from SEC Form 13F as of September 30, 2025.