AMBAC FINANCIAL GROUP INC (AMBC) Top Institutional Shareholders
AMBAC FINANCIAL GROUP INC (AMBC) 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 $149.22M in AMBC holdings during the latest filing period.
Blackrock, Inc. is currently the largest disclosed institutional shareholder of AMBC tracked by InsiderSet, reporting ownership valued at approximately $18.22M in its March 31, 2026 SEC Form 13F filing.
The top 10 institutional shareholders tracked on this page collectively account for approximately 54% of the total disclosed AMBC value among the investors covered in this analysis. Major shareholders include Blackrock, Inc., Western Standard Llc, Vanguard Capital Management Llc, and several other long-term asset managers with concentrated positions in AMBAC FINANCIAL GROUP INC (AMBC).
This page ranks the largest institutional AMBC 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
145
Total Reported Value
$149.22M
Largest Holder
Blackrock, Inc.
Largest Position
$18.22M
Insider Transactions (90d)
0
Latest Filing Quarter
Q1 2026
New Institutional Positions
181
Funds Exiting Positions
0
| Name | Investor/Manager | Portfolio % | Quantity | Reported Balance | Current Estimated Value | Gain/loss Since Filing | Estimated Portfolio Performance |
|---|---|---|---|---|---|---|---|
| Blackrock, Inc. | 0.00% | 3,917,798 | $18,217,762 | — | — | — | |
| Western Standard Llc | 5.50% | 2,247,591 | $10,451,298 | — | — | — | |
| Vanguard Capital Management Llc | 0.00% | 1,945,076 | $9,044,603 | — | — | — | |
| Prescott Group Capital Management, L.L.C. | 0.74% | 1,592,587 | $7,405,530 | — | — | — | |
| Wolf Hill Capital Management, Lp | 0.97% | 1,470,334 | $6,837,053 | — | — | — | |
| Gendell Jeffrey L | 0.09% | 1,413,212 | $6,571,436 | — | — | — | |
| Third Avenue Management | Marty Whitman | 1.01% | 1,341,211 | $6,236,631 | — | — | — |
| Dimensional Fund Advisors Lp | 0.00% | 1,310,132 | $6,092,068 | — | — | — | |
| Bain Capital Credit, Lp | 1.70% | 1,108,012 | $5,152,256 | — | — | — | |
| Marshall Wace, Llp | 0.01% | 1,065,335 | $4,953,807 | — | — | — | |
| Geode Capital Management, Llc | 0.00% | 1,022,438 | $4,755,504 | — | — | — | |
| State Street Corp | 0.00% | 941,404 | $4,377,529 | — | — | — | |
| Jacobs Levy Equity Management, Inc | 0.02% | 884,272 | $4,111,865 | — | — | — | |
| Nuveen, Llc | 0.00% | 800,253 | $3,721,176 | — | — | — | |
| Jane Street Group, Llc | 0.00% | 764,384 | $3,554,385 | — | — | — | |
| Caption Management, Llc | 0.14% | 642,597 | $2,988,076 | — | — | — | |
| Bracebridge Capital, Llc | 0.48% | 579,234 | $2,693,438 | — | — | — | |
| Riho Partners, Llc | 1.61% | 546,569 | $2,541,546 | — | — | — | |
| Citadel Advisors Llc | 0.00% | 431,809 | $2,007,912 | — | — | — | |
| Essex Investment Management Co Llc | 0.31% | 418,203 | $1,944,644 | — | — | — | |
| Susquehanna International Group, Llp | 0.00% | 390,193 | $1,814,397 | — | — | — | |
| Goldman Sachs Group Inc | 0.00% | 346,293 | $1,610,263 | — | — | — | |
| Ipg Investment Advisors Llc | 0.26% | 325,616 | $1,514,114 | — | — | — | |
| Brooklyn Investment Group | 0.05% | 325,351 | $1,512,883 | — | — | — | |
| Northern Trust Corp | 0.00% | 322,348 | $1,498,918 | — | — | — | |
| Vanguard Portfolio Management Llc | 0.00% | 295,900 | $1,375,935 | — | — | — | |
| Charles Schwab Investment Management Inc | 0.00% | 295,344 | $1,373,350 | — | — | — | |
| Vanguard Fiduciary Trust Co | 0.00% | 274,562 | $1,276,713 | — | — | — | |
| Ubs Group Ag | 0.00% | 264,280 | $1,228,902 | — | — | — | |
| Bank Of America Corp | 0.00% | 256,110 | $1,190,911 | — | — | — | |
| Morgan Stanley | 0.00% | 235,246 | $1,093,894 | — | — | — | |
| Renaissance Technologies LLC | Jim Simons | 0.00% | 227,726 | $1,058,926 | — | — | — |
| Harbor Advisors Llc | 0.13% | 196,382 | $913,176 | — | — | — | |
| Bridgeway Capital Management, Llc | 0.02% | 182,504 | $848,644 | — | — | — | |
| Russell Investments Group, Ltd. | 0.00% | 181,271 | $842,911 | — | — | — | |
| Tudor Investment Corp Et Al | 0.00% | 159,963 | $743,828 | — | — | — | |
| Sei Investments Co | 0.00% | 156,078 | $725,774 | — | — | — | |
| Invesco Ltd. | 0.00% | 151,042 | $702,345 | — | — | — | |
| Connor, Clark & Lunn Investment Management Ltd. | 0.00% | 144,301 | $671,000 | — | — | — | |
| Arrowpoint Investment Partners (Singapore) Pte. Ltd. | 0.94% | 139,168 | $647,131 | — | — | — | |
| Millennium Management Llc | 0.00% | 135,088 | $628,159 | — | — | — | |
| Legato Capital Management Llc | 0.06% | 130,760 | $608,034 | — | — | — | |
| Bank Of New York Mellon Corp | 0.00% | 130,471 | $606,688 | — | — | — | |
| American Century Companies Inc | 0.00% | 120,540 | $560,511 | — | — | — | |
| Xtx Topco Ltd | 0.01% | 116,911 | $543,636 | — | — | — | |
| Ameriprise Financial Inc | 0.00% | 115,045 | $534,959 | — | — | — | |
| Empowered Funds, Llc | 0.00% | 114,004 | $530,119 | — | — | — | |
| Point72 Asset Management, L.P. | 0.00% | 113,656 | $528,500 | — | — | — | |
| Cruiser Capital Advisors, Llc | 0.20% | 108,798 | $505,910 | — | — | — | |
| Hsbc Holdings Plc | 0.00% | 102,430 | $476,300 | — | — | — |
Frequently asked questions about AMBC
Who owns the most AMBC stock?
The largest holders of AMBC 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 AMBAC FINANCIAL GROUP INC (AMBC).
Is AMBC widely held by superinvestors?
Many widely followed stocks like AMBC appear across numerous superinvestor portfolios because of liquidity, index inclusion, and fundamentals. The holder count and table above show how broadly AMBC 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.