ACTINIUM PHARMACEUTICALS INC (ATNM) Top Institutional Shareholders
ACTINIUM PHARMACEUTICALS INC (ATNM) is currently reported in institutional portfolios tracked by InsiderSet based on the latest available SEC Form 13F filings for the quarter ended March 31, 2026. The institutional investors covered on this page collectively reported approximately $4.64M in ATNM holdings during the latest filing period.
Vanguard Capital Management Llc is currently the largest disclosed institutional shareholder of ATNM tracked by InsiderSet, reporting ownership valued at approximately $1.25M in its March 31, 2026 SEC Form 13F filing. Based on current market prices and the latest disclosed share count, the position is now estimated to be worth approximately $1.28M, representing an estimated gain of +2.51% since the filing period.
The top 10 institutional shareholders tracked on this page collectively account for approximately 85% of the total disclosed ATNM value among the investors covered in this analysis. Major shareholders include Vanguard Capital Management Llc, Millennium Management Llc, Renaissance Technologies LLC, and several other long-term asset managers with concentrated positions in ACTINIUM PHARMACEUTICALS INC (ATNM).
This page ranks the largest institutional ATNM shareholders using publicly disclosed SEC Form 13F data, including reported values, estimated current holding values, portfolio allocation percentages, ownership concentration metrics, and historical holding changes across major hedge funds and investment firms.
Institutional Holders
52
Total Reported Value
$4.64M
Largest Holder
Vanguard Capital Management Llc
Largest Position
$1.25M
Insider Transactions (90d)
0
Latest Filing Quarter
Q1 2026
New Institutional Positions
66
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Vanguard Capital Management Llc | 0.00% | 1,255,516 | $1,249,238 | $1,280,626 | +$31,388 | +2.51% | |
| Millennium Management Llc | 0.00% | 564,600 | $561,946 | $575,892 | +$13,946 | +2.48% | |
| Renaissance Technologies LLC | Jim Simons | 0.00% | 471,600 | $469,383 | $481,032 | +$11,649 | +2.48% |
| Blackrock, Inc. | 0.00% | 371,210 | $369,466 | $378,634 | +$9,168 | +2.48% | |
| Two Sigma Investments, Lp | 0.00% | 337,168 | $335,583 | $343,911 | +$8,328 | +2.48% | |
| Geode Capital Management, Llc | 0.00% | 336,073 | $334,594 | $342,794 | +$8,200 | +2.45% | |
| Gagnon Securities Llc | 0.05% | 201,300 | $200,354 | $205,326 | +$4,972 | +2.48% | |
| Vanguard Fiduciary Trust Co | 0.00% | 160,265 | $159,464 | $163,470 | +$4,006 | +2.51% | |
| State Street Corp | 0.00% | 126,215 | $125,622 | $128,739 | +$3,117 | +2.48% | |
| Susquehanna International Group, Llp | 0.00% | 123,998 | $123,415 | $126,478 | +$3,063 | +2.48% | |
| Gen-Wealth Partners Inc | 0.03% | 107,111 | $106,608 | $109,253 | +$2,645 | +2.48% | |
| Northern Trust Corp | 0.00% | 75,855 | $75,498 | $77,372 | +$1,874 | +2.48% | |
| Goldman Sachs Group Inc | 0.00% | 70,241 | $69,911 | $71,646 | +$1,735 | +2.48% | |
| Bridgeway Capital Management, Llc | 0.00% | 40,000 | $39,812 | $40,800 | +$988 | +2.48% | |
| Two Sigma Securities, Llc | 0.00% | 35,887 | $35,718 | $36,605 | +$887 | +2.48% | |
| Nine Masts Capital Ltd | 0.01% | 35,227 | $35,061 | $35,932 | +$871 | +2.48% | |
| Dimensional Fund Advisors Lp | 0.00% | 34,923 | $34,759 | $35,621 | +$862 | +2.48% | |
| Jane Street Group, Llc | 0.00% | 34,299 | $34,137 | $34,985 | +$848 | +2.48% | |
| Xtx Topco Ltd | 0.00% | 30,210 | $30,068 | $30,814 | +$746 | +2.48% | |
| Vontobel Holding Ltd. | 0.00% | 30,000 | $29,859 | $30,600 | +$741 | +2.48% | |
| Gerald Baker Financial Group Llc | 0.01% | 22,691 | $28,591 | $23,145 | -$5,446 | -19.05% | |
| Mayport, Llc | 0.00% | 22,000 | $21,897 | $22,440 | +$543 | +2.48% | |
| North Star Asset Management Inc | 0.00% | 20,000 | $19,906 | $20,400 | +$494 | +2.48% | |
| Osaic Holdings, Inc. | 0.00% | 19,865 | $19,852 | $20,262 | +$410 | +2.07% | |
| Wells Fargo & Company/Mn | 0.00% | 19,800 | $19,707 | $20,196 | +$489 | +2.48% | |
| Qube Research & Technologies Ltd | 0.00% | 18,048 | $17,963 | $18,409 | +$446 | +2.48% | |
| Ubs Group Ag | 0.00% | 14,618 | $14,545 | $14,910 | +$365 | +2.51% | |
| Morgan Stanley | 0.00% | 13,597 | $13,533 | $13,869 | +$336 | +2.48% | |
| Callan Family Office, Llc | 0.00% | 11,944 | $11,888 | $12,183 | +$295 | +2.48% | |
| Intrepid Financial Planning Group Llc | 0.00% | 10,500 | $10,451 | $10,710 | +$259 | +2.48% | |
| Level Four Advisory Services, Llc | 0.00% | 10,000 | $9,953 | $10,200 | +$247 | +2.48% | |
| Savvy Advisors, Inc. | 0.00% | 10,000 | $9,953 | $10,200 | +$247 | +2.48% | |
| Vanguard Global Advisers, Llc | 0.00% | 8,893 | $8,849 | $9,071 | +$222 | +2.51% | |
| Rockefeller Capital Management L.P. | 0.00% | 4,000 | $3,981 | $4,080 | +$99 | +2.49% | |
| Steward Partners Investment Advisory, Llc | 0.00% | 2,166 | $2,156 | $2,209 | +$53 | +2.47% | |
| Advisory Services Network, Llc | 0.00% | 1,460 | $1,453 | $1,489 | +$36 | +2.49% | |
| Federated Hermes, Inc. | 0.00% | 1,403 | $1,396 | $1,431 | +$35 | +2.51% | |
| National Bank Of Canada | 0.00% | 1,021 | $1,002 | $1,041 | +$39 | +3.93% | |
| Citigroup Inc | 0.00% | 678 | $675 | $692 | +$17 | +2.45% | |
| Acadian Asset Management Llc | 0.00% | 600,819 | $596 | $612,835 | +$612,239 | +102724.73% | |
| Sbi Securities Co., Ltd. | 0.00% | 542 | $539 | $553 | +$14 | +2.57% | |
| Jones Financial Companies Lllp | 0.00% | 351 | $362 | $358 | -$4 | -1.10% | |
| Cwm, Llc | 0.00% | 351 | $349 | $358 | +$9 | +2.58% | |
| Pittenger & Anderson Inc | 0.00% | 341 | $340 | $348 | +$8 | +2.30% | |
| Nisa Investment Advisors, Llc | 0.00% | 330 | $328 | $337 | +$9 | +2.62% | |
| Investors Research Corp | 0.00% | 300 | $299 | $306 | +$7 | +2.34% | |
| Bnp Paribas Financial Markets | 0.00% | 237 | $236 | $242 | +$6 | +2.43% | |
| Northwestern Mutual Wealth Management Co | 0.00% | 107 | $106 | $109 | +$3 | +2.96% | |
| Fmr Llc | 0.00% | 79 | $79 | $81 | +$2 | +2.00% | |
| Am Investment Strategies Llc | 0.01% | 29,356 | $29 | $29,943 | +$29,914 | +103152.14% |
Frequently asked questions about ATNM
Who owns the most ATNM stock?
The largest holders of ATNM are typically major institutional investors such as asset managers and hedge funds reporting on Form 13F. The table above ranks tracked superinvestors by reported position size using the latest available filings for ACTINIUM PHARMACEUTICALS INC (ATNM).
Is ATNM widely held by superinvestors?
Many widely followed stocks like ATNM appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly ATNM is represented among the institutional managers we track.
What do “Current Estimated Value”, “Gain/loss Since Filing”, and “Estimated Portfolio Performance” mean?
Current Estimated Value is reported share quantity from the latest 13F times our most recent split-adjusted U.S. session close. Gain/loss Since Filing is that estimate minus the reported 13F dollar value; Estimated Portfolio Performance is that difference as a percent of the reported value. Green means the estimate is above the filing value; red means below (not purchase cost). If many filers share the same implied filing price per share, the performance % may match across rows. These are not official fund marks or live quotes.