Actinium Pharmaceuticals, Inc.
Actinium Pharmaceuticals, Inc. (ATNM) Stock Ownership
Institutional vs insider vs public ownership from 13F and float data — top holders, activity, and insider trades below.
SEC 13F · FMP · ATNM · as of Sep 30, 2025
Ownership Breakdown
63
Institutional Holders
▼ 2 vs Q2
$8.23M
Total Inst. Value
▲ $550,288 vs Q2
31.37M
Shares Outstanding
freeFloat 98.92%
5.15M
13F Shares Held
▼ 341,120 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
ATNM largest shareholders · institutional ownership
Q3 2025 · SEC 13F
Showing top 10 holders
| Holder | Shares | % Owned | Weight | Value | Reported | Change |
|---|---|---|---|---|---|---|
VANGUARD GROUP INC pharmaceutical preparations | 1.38M | 4.44% | 4.44% | $2.22B | Nov 7, 2025 | ▲ 12.7K |
MILLENNIUM MANAGEMENT LLC pharmaceutical preparations | 624.7K | 2.00% | 2.00% | $999.51M | Nov 14, 2025 | ▼ 38.6K |
ACADIAN ASSET MANAGEMENT LLC pharmaceutical preparations | 489.6K | 1.57% | 1.57% | $782.00M | Nov 13, 2025 | ▼ 2.4K |
BLACKROCK, INC. pharmaceutical preparations | 363.5K | 1.17% | 1.17% | $581.58M | Nov 12, 2025 | ▼ 104.2K |
GEODE CAPITAL MANAGEMENT, LLC pharmaceutical preparations | 328.4K | 1.05% | 1.05% | $525.63M | Nov 12, 2025 | ▼ 1.3K |
RENAISSANCE TECHNOLOGIES LLC pharmaceutical preparations | 288.6K | 92.52% | 92.52% | $461.81M | Nov 13, 2025 | ▲ 79.1K |
TWO SIGMA INVESTMENTS, LP pharmaceutical preparations | 234.3K | 75.10% | 75.10% | $374.87M | Nov 14, 2025 | ▲ 187.7K |
GAGNON SECURITIES LLC pharmaceutical preparations | 226.3K | 72.53% | 72.53% | $362.01M | Nov 3, 2025 | ▼ 365 |
TWO SIGMA ADVISERS, LP pharmaceutical preparations | 196.4K | 62.95% | 62.95% | $314.20M | Nov 14, 2025 | NEW |
CITADEL ADVISORS LLC pharmaceutical preparations | 126.6K | 40.59% | 40.59% | $202.58M | Nov 14, 2025 | ▲ 71.6K |
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
10
Increased
+412.0K shares7
New Positions
first time holders23
Decreased
−695.5K shares0
Sold Out
fully exitedNet shares change (top 50)
283.5K
+412.0K / −695.5K
Net new holders
-6
7 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
ATNM insider trading · insider activity
Source: SEC Form 4
0
Buy transactions
1
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 |
|---|---|---|---|---|---|---|---|
SETH SANDESH Chief Executive Officer | Aug 18, 2025 | Tax Withhold | 120,900 | $1.71 | $206.7K | 184.5K | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 72,156 | $4.96 | $357.9K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 8,333 | $9.55 | $79.6K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 2,500 | $41.70 | $104.3K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 2,500 | $23.49 | $58.7K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 70,311 | $5.00 | $351.6K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 18,351 | $6.07 | $111.4K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 8,333 | $6.96 | $58.0K | 0 | Form 4 ↗ |
Steinhart Richard I director | Mar 31, 2025 | D-Return | 2,500 | $59.70 | $149.3K | 0 | Form 4 ↗ |
Chell Jeffrey W. director | Mar 31, 2025 | D-Return | 2,500 | $10.41 | $26.0K | 0 | 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
Actinium Pharmaceuticals, Inc. (ATNM) is primarily owned by institutional investors, who hold approximately 16.4% of total shares outstanding. Company insiders own approximately 1.08%, while retail and public investors account for the remaining 82.51%.
The largest institutional shareholder of Actinium Pharmaceuticals, Inc. is VANGUARD GROUP INC, holding approximately 1.38 million shares — equal to 4.44% of outstanding shares — as of September 30, 2025.
A total of 63 institutional investors currently hold ATNM stock, with a combined institutional value of approximately $8,234,574 as of the most recent 13F filing period.
Frequently asked questions
ATNM ownershipActinium Pharmaceuticals, Inc. (ATNM) is primarily owned by institutional investors, who hold approximately 16.4% of shares. The largest shareholder is VANGUARD GROUP INC with a 4.44% stake. Company insiders hold 1.08%. Data sourced from SEC Form 13F as of September 30, 2025.