On this page, we present all of the funds holding AMBC from our database of 13F filers, detailed in the table below. The first column indicates the name of each of the funds holding AMBC, with a link to that fund's top holdings. The next columns indicate the amount of AMBC stock held by each of the funds holding AMBC, followed by the AMBC position size held by the fund, and lastly the date of the quarterly filing period the data represents. In total, we count 173 funds holding AMBC within the last two filing periods in our coverage universe of 13F filers, with the largest position size having been reported by BlackRock Inc.. For more details on the positions held by BlackRock Inc. (or by any of the other funds holding AMBC), click the fund name in the "Holder" column of the funds-holding-AMBC table below.

Holder	Amount	Position Size ($ in 1000's)	As of
BlackRock Inc.	7,285,404	$120,063	12/31/2023
AMBC	7,285,404	$120,063	12/31/2023
Vanguard Group Inc.	4,835,365	$79,687	12/31/2023
AMBC	4,835,365	$79,687	12/31/2023
Dimensional Fund Advisors LP	2,603,679	$42,908	12/31/2023
AMBC	2,603,679	$42,908	12/31/2023
FMR LLC	2,075,509	$34,204	12/31/2023
AMBC	2,075,509	$34,204	12/31/2023
Repertoire Partners LP		$30,194	12/31/2023
Call	1,266,900	$20,879	12/31/2023
AMBC	565,233	$9,315	12/31/2023
State Street Corp	1,626,127	$26,799	12/31/2023
AMBC	1,626,127	$26,799	12/31/2023
Invesco Ltd.	1,032,814	$17,021	12/31/2023
AMBC	1,032,814	$17,021	12/31/2023
Geode Capital Management LLC	946,179	$15,595	12/31/2023
AMBC	946,179	$15,595	12/31/2023
Boussard & Gavaudan Investment Management LLP	853,531	$13,887	12/31/2023
AMBC	853,531	$13,887	12/31/2023
Bracebridge Capital LLC	799,234	$13,171	12/31/2023
AMBC	799,234	$13,171	12/31/2023
Nuveen Asset Management LLC	756,478	$12,467	12/31/2023
AMBC	756,478	$12,467	12/31/2023
Deutsche Bank AG	740,430	$12,202	12/31/2023
AMBC	740,430	$12,202	12/31/2023
Prudential Financial Inc.	730,120	$12,032	12/31/2023
AMBC	730,120	$12,032	12/31/2023
Susquehanna International Group LLP		$11,314	12/31/2023
Call	456,100	$7,517	12/31/2023
AMBC	280,112	$4,616	12/31/2023
Put	49,700	$819	12/31/2023
Goldman Sachs Group Inc.	649,686	$10,707	12/31/2023
AMBC	649,686	$10,707	12/31/2023
Charles Schwab Investment Management Inc.	649,577	$10,705	12/31/2023
AMBC	649,577	$10,705	12/31/2023
Morgan Stanley	551,190	$9,084	12/31/2023
AMBC	551,190	$9,084	12/31/2023
American Century Companies Inc.	519,702	$8,565	12/31/2023
AMBC	519,702	$8,565	12/31/2023
Northern Trust Corp	504,697	$8,317	12/31/2023
AMBC	504,697	$8,317	12/31/2023
D. E. Shaw & Co. Inc.	491,719	$8,104	12/31/2023
AMBC	491,719	$8,104	12/31/2023
Simplex Trading LLC		$8,067	12/31/2023
AMBC	333,361	$5,493	12/31/2023
Call	163,700	$2,697	12/31/2023
Put	7,500	$123	12/31/2023
Bank of New York Mellon Corp	470,976	$7,762	12/31/2023
AMBC	470,976	$7,762	12/31/2023
Citadel Advisors LLC		$7,541	12/31/2023
AMBC	404,310	$6,663	12/31/2023
Call	167,800	$2,765	12/31/2023
Put	114,500	$1,887	12/31/2023
Walleye Trading LLC		$7,104	12/31/2023
AMBC	471,975	$7,778	12/31/2023
Put	46,300	$763	12/31/2023
Call	5,400	$89	12/31/2023
Jupiter Asset Management Ltd.	426,663	$7,031	12/31/2023
AMBC	426,663	$7,031	12/31/2023
Bridgeway Capital Management Inc.	390,922	$6,442	12/31/2023
AMBC	390,922	$6,442	12/31/2023
Hotchkis & Wiley Capital Management LLC	386,530	$6,370	12/31/2023
AMBC	386,530	$6,370	12/31/2023
AQR Capital Management LLC	367,839	$6,062	12/31/2023
AMBC	367,839	$6,062	12/31/2023
Hsbc Holdings PLC	301,777	$4,919	12/31/2023
AMBC	301,777	$4,919	12/31/2023
Principal Financial Group Inc.	263,679	$4,345	12/31/2023
AMBC	263,679	$4,345	12/31/2023
Jane Street Group LLC		$3,692	12/31/2023
AMBC	199,059	$3,280	12/31/2023
Call	25,000	$412	12/31/2023
UBS Group AG		$3,390	12/31/2023
Call	177,500	$2,925	12/31/2023
AMBC	28,204	$465	12/31/2023
Caption Management LLC		$3,381	12/31/2023
AMBC	125,210	$2,063	12/31/2023
Call	80,000	$1,318	12/31/2023
Gendell Jeffrey L	199,255	$3,284	12/31/2023
AMBC	199,255	$3,284	12/31/2023
Harbor Advisors LLC	196,382	$3,236	12/31/2023
AMBC	196,382	$3,236	12/31/2023
Ameriprise Financial Inc.	189,336	$3,120	12/31/2023
AMBC	189,336	$3,120	12/31/2023
Renaissance Technologies LLC	186,744	$3,078	12/31/2023
AMBC	186,744	$3,078	12/31/2023
Public Sector Pension Investment Board	165,792	$2,732	12/31/2023
AMBC	165,792	$2,732	12/31/2023
Voya Investment Management LLC	165,627	$2,730	12/31/2023
AMBC	165,627	$2,730	12/31/2023
Russell Investments Group Ltd.	157,407	$2,594	12/31/2023
AMBC	157,407	$2,594	12/31/2023
Empowered Funds LLC	141,627	$2,334	12/31/2023
AMBC	141,627	$2,334	12/31/2023
Rhumbline Advisers	135,245	$2,229	12/31/2023
AMBC	135,245	$2,229	12/31/2023
Wells Fargo & Company MN		$2,182	12/31/2023
AMBC	127,786	$2,106	12/31/2023
Call	4,600	$76	12/31/2023
Group One Trading L.P.		$2,166	12/31/2023
AMBC	86,430	$1,424	12/31/2023
Call	45,000	$742	12/31/2023
GTS Securities LLC	129,982	$2,142	12/31/2023
AMBC	129,982	$2,142	12/31/2023
Legal & General Group Plc	124,907	$2,058	12/31/2023
AMBC	124,907	$2,058	12/31/2023
First Trust Advisors LP	124,197	$2,047	12/31/2023
AMBC	124,197	$2,047	12/31/2023
Brandywine Global Investment Management LLC	122,146	$2,013	12/31/2023
AMBC	122,146	$2,013	12/31/2023
Gator Capital Management LLC	121,435	$2,001	12/31/2023
AMBC	121,435	$2,001	12/31/2023
Bank of America Corp DE	109,200	$1,800	12/31/2023
AMBC	109,200	$1,800	12/31/2023
Credit Suisse AG	104,142	$1,716	12/31/2023
AMBC	104,142	$1,716	12/31/2023
Barclays PLC	96,322	$1,588	12/31/2023
AMBC	96,322	$1,588	12/31/2023
Walleye Capital LLC	93,614	$1,543	12/31/2023
AMBC	93,614	$1,543	12/31/2023
Exchange Traded Concepts LLC	96,166	$1,503	03/31/2024
AMBC	96,166	$1,503	03/31/2024
Assetmark Inc.	91,123	$1,502	12/31/2023
AMBC	91,123	$1,502	12/31/2023
WINTON GROUP Ltd	89,732	$1,479	12/31/2023
AMBC	89,732	$1,479	12/31/2023
Swiss National Bank	89,200	$1,470	12/31/2023
AMBC	89,200	$1,470	12/31/2023
Los Angeles Capital Management & Equity Research Inc.	87,291	$1,364	03/31/2024
AMBC	87,291	$1,364	03/31/2024
Guggenheim Capital LLC	80,137	$1,321	12/31/2023
AMBC	80,137	$1,321	12/31/2023
Millennium Management LLC	76,458	$1,260	12/31/2023
AMBC	76,458	$1,260	12/31/2023
Federated Hermes Inc.	76,134	$1,255	12/31/2023
AMBC	76,134	$1,255	12/31/2023
Norges Bank	75,000	$1,236	12/31/2023
AMBC	75,000	$1,236	12/31/2023
Caxton Associates LP	66,203	$1,091	12/31/2023
AMBC	66,203	$1,091	12/31/2023
Allianz Asset Management GmbH	61,266	$1,010	12/31/2023
AMBC	61,266	$1,010	12/31/2023
UBS Asset Management Americas Inc.	59,394	$979	12/31/2023
AMBC	59,394	$979	12/31/2023
LPL Financial LLC	57,998	$956	12/31/2023
AMBC	57,998	$956	12/31/2023
State of Tennessee Treasury Department	57,135	$942	12/31/2023
AMBC	57,135	$942	12/31/2023
Royce & Associates LP	57,074	$941	12/31/2023
AMBC	57,074	$941	12/31/2023
Man Group plc	52,817	$870	12/31/2023
AMBC	52,817	$870	12/31/2023
California State Teachers Retirement System	47,629	$785	12/31/2023
AMBC	47,629	$785	12/31/2023
New York State Teachers Retirement System	44,830	$739	12/31/2023
AMBC	44,830	$739	12/31/2023
State of Wisconsin Investment Board	44,597	$735	12/31/2023
AMBC	44,597	$735	12/31/2023
Wolverine Trading LLC	42,897	$707	12/31/2023
AMBC	42,897	$707	12/31/2023
Thrivent Financial for Lutherans	40,272	$664	12/31/2023
AMBC	40,272	$664	12/31/2023
Great West Life Assurance Co. Can	40,202	$662	12/31/2023
AMBC	40,202	$662	12/31/2023
Alliancebernstein L.P.	39,620	$653	12/31/2023
AMBC	39,620	$653	12/31/2023
Texas Permanent School Fund	38,784	$639	12/31/2023
AMBC	38,784	$639	12/31/2023
JPMorgan Chase & Co.	37,942	$625	12/31/2023
AMBC	37,942	$625	12/31/2023
Algert Global LLC	36,950	$609	12/31/2023
AMBC	36,950	$609	12/31/2023
Price T Rowe Associates Inc. MD	36,544	$603	12/31/2023
AMBC	36,544	$603	12/31/2023
Teacher Retirement System of Texas	35,844	$591	12/31/2023
AMBC	35,844	$591	12/31/2023
Healthcare of Ontario Pension Plan Trust Fund	33,600	$554	12/31/2023
AMBC	33,600	$554	12/31/2023
Squarepoint Ops LLC	33,415	$551	12/31/2023
AMBC	33,415	$551	12/31/2023
ClearAlpha Technologies LP	30,999	$511	12/31/2023
AMBC	30,999	$511	12/31/2023
IMC Chicago LLC		$509	03/31/2024
AMBC	71,988	$1,125	03/31/2024
Put	60,000	$938	03/31/2024
Call	20,600	$322	03/31/2024
ExodusPoint Capital Management LP	30,137	$497	12/31/2023
AMBC	30,137	$497	12/31/2023
Yousif Capital Management LLC	29,420	$485	12/31/2023
AMBC	29,420	$485	12/31/2023
Citigroup Inc.	28,016	$462	12/31/2023
AMBC	28,016	$462	12/31/2023
HighTower Advisors LLC	27,275	$454	12/31/2023
AMBC	27,275	$454	12/31/2023
Franklin Resources Inc.	27,347	$451	12/31/2023
AMBC	27,347	$451	12/31/2023
Illinois Municipal Retirement Fund	26,645	$439	12/31/2023
AMBC	26,645	$439	12/31/2023
State of Alaska Department of Revenue	27,533	$430	03/31/2024
AMBC	27,533	$430	03/31/2024
Ensign Peak Advisors Inc	25,350	$418	12/31/2023
AMBC	25,350	$418	12/31/2023
MetLife Investment Management LLC	24,566	$405	12/31/2023
AMBC	24,566	$405	12/31/2023
Truist Financial Corp	24,325	$401	12/31/2023
AMBC	24,325	$401	12/31/2023
American International Group Inc.	24,127	$398	12/31/2023
AMBC	24,127	$398	12/31/2023
PDT Partners LLC	23,169	$382	12/31/2023
AMBC	23,169	$382	12/31/2023
Sei Investments Co.	22,835	$376	12/31/2023
AMBC	22,835	$376	12/31/2023
Louisiana State Employees Retirement System	22,600	$372	12/31/2023
AMBC	22,600	$372	12/31/2023
Mraz Amerine & Associates Inc.	22,600	$372	12/31/2023
AMBC	22,600	$372	12/31/2023
Cresset Asset Management LLC	22,537	$371	12/31/2023
AMBC	22,537	$371	12/31/2023
Comerica Bank	20,658	$340	12/31/2023
AMBC	20,658	$340	12/31/2023
Verition Fund Management LLC	20,406	$336	12/31/2023
AMBC	20,406	$336	12/31/2023
Janus Henderson Group PLC	20,019	$330	12/31/2023
AMBC	20,019	$330	12/31/2023
Mirae Asset Global Investments Co. Ltd.	19,837	$327	12/31/2023
AMBC	19,837	$327	12/31/2023
Interval Partners LP	19,762	$326	12/31/2023
AMBC	19,762	$326	12/31/2023
Graham Capital Management L.P.	19,584	$323	12/31/2023
AMBC	19,584	$323	12/31/2023
Envestnet Asset Management Inc.	18,597	$306	12/31/2023
AMBC	18,597	$306	12/31/2023
Amalgamated Bank	17,075	$281	12/31/2023
AMBC	17,075	$281	12/31/2023
Royal Bank of Canada	16,449	$272	12/31/2023
AMBC	16,449	$272	12/31/2023
The Manufacturers Life Insurance Company	16,185	$267	12/31/2023
AMBC	16,185	$267	12/31/2023
Maryland State Retirement & Pension System	16,687	$261	03/31/2024
AMBC	16,687	$261	03/31/2024
HRT Financial LP	15,859	$261	12/31/2023
AMBC	15,859	$261	12/31/2023
GSA Capital Partners LLP	15,183	$250	12/31/2023
AMBC	15,183	$250	12/31/2023
BNP Paribas Arbitrage SA	15,052	$248	12/31/2023
AMBC	15,052	$248	12/31/2023
New York State Common Retirement Fund	14,985	$247	12/31/2023
AMBC	14,985	$247	12/31/2023
Balyasny Asset Management LLC	14,857	$245	12/31/2023
AMBC	14,857	$245	12/31/2023
KLCM Advisors Inc.	14,000	$231	12/31/2023
AMBC	14,000	$231	12/31/2023
Pathstone Holdings LLC	13,298	$219	12/31/2023
AMBC	13,298	$219	12/31/2023
Oregon Public Employees Retirement Fund	13,198	$218	12/31/2023
AMBC	13,198	$218	12/31/2023
Deerfield Management Company L.P. Series C	12,673	$209	12/31/2023
AMBC	12,673	$209	12/31/2023
Arizona State Retirement System	12,664	$209	12/31/2023
AMBC	12,664	$209	12/31/2023
State Board of Administration of Florida Retirement System	12,630	$208	12/31/2023
AMBC	12,630	$208	12/31/2023
Teachers Retirement System of The State of Kentucky	12,301	$202	12/31/2023
AMBC	12,301	$202	12/31/2023
State of Wyoming	12,111	$200	12/31/2023
AMBC	12,111	$200	12/31/2023
Everence Capital Management Inc.	10,910	$180	12/31/2023
AMBC	10,910	$180	12/31/2023
Cornerstone Investment Partners LLC	10,807	$178	12/31/2023
AMBC	10,807	$178	12/31/2023
Tower Research Capital LLC TRC	10,809	$178	12/31/2023
AMBC	10,809	$178	12/31/2023
Schonfeld Strategic Advisors LLC	10,100	$166	12/31/2023
AMBC	10,100	$166	12/31/2023
Allspring Global Investments Holdings LLC	10,542	$165	03/31/2024
AMBC	10,542	$165	03/31/2024
Victory Capital Management Inc.	10,000	$165	12/31/2023
AMBC	10,000	$165	12/31/2023
Long Focus Capital Management LLC	10,000	$165	12/31/2023
AMBC	10,000	$165	12/31/2023
Zurcher Kantonalbank Zurich Cantonalbank	8,189	$135	12/31/2023
AMBC	8,189	$135	12/31/2023
Advisor Group Holdings Inc.	7,268	$120	12/31/2023
AMBC	7,268	$120	12/31/2023
Amundi	6,006	$94	12/31/2023
AMBC	6,006	$94	12/31/2023
Ameritas Investment Partners Inc.	4,583	$76	12/31/2023
AMBC	4,583	$76	12/31/2023
Nisa Investment Advisors LLC	3,014	$50	12/31/2023
AMBC	3,014	$50	12/31/2023
The PNC Financial Services Group Inc.	2,613	$43	12/31/2023
AMBC	2,613	$43	12/31/2023
Gladius Capital Management LP	2,638	$43	12/31/2023
AMBC	2,638	$43	12/31/2023
Metropolitan Life Insurance Co NY	2,437	$40	12/31/2023
AMBC	2,437	$40	12/31/2023
Aquatic Capital Management LLC	2,100	$35	12/31/2023
AMBC	2,100	$35	12/31/2023
KBC Group NV	1,666	$27	12/31/2023
AMBC	1,666	$27	12/31/2023
Covestor Ltd	1,556	$26	12/31/2023
AMBC	1,556	$26	12/31/2023
Lazard Asset Management LLC	1,371	$22	12/31/2023
AMBC	1,371	$22	12/31/2023
Public Employees Retirement System of Ohio	1,170	$19	12/31/2023
AMBC	1,170	$19	12/31/2023
US Bancorp DE	980	$16	12/31/2023
AMBC	980	$16	12/31/2023
AJOVista LLC	626	$10	12/31/2023
AMBC	626	$10	12/31/2023
Lindbrook Capital LLC	549	$9	12/31/2023
AMBC	549	$9	12/31/2023
West Tower Group LLC	479	$8	12/31/2023
AMBC	479	$8	12/31/2023
Wiser Advisor Group LLC	500	$8	12/31/2023
AMBC	500	$8	12/31/2023
Fifth Third Bancorp	429	$7	12/31/2023
AMBC	429	$7	12/31/2023
Huntington National Bank	381	$6	12/31/2023
AMBC	381	$6	12/31/2023
Quarry LP	353	$6	12/31/2023
AMBC	353	$6	12/31/2023
Fortitude Family Office LLC	329	$5	03/31/2024
AMBC	329	$5	03/31/2024
GAMMA Investing LLC	339	$5	03/31/2024
AMBC	339	$5	03/31/2024
Bessemer Group Inc.	293	$5	12/31/2023
AMBC	293	$5	12/31/2023
Capital Analysts LLC	325	$5	12/31/2023
AMBC	325	$5	12/31/2023
Quadrant Capital Group LLC	322	$5	12/31/2023
AMBC	322	$5	12/31/2023
Qube Research & Technologies Ltd	333	$5	12/31/2023
AMBC	333	$5	12/31/2023
Red Tortoise LLC	180	$3	03/31/2024
AMBC	180	$3	03/31/2024
DiNuzzo Private Wealth Inc.	177	$3	12/31/2023
AMBC	177	$3	12/31/2023
Barrow Hanley Mewhinney & Strauss LLC	150	$2	12/31/2023
AMBC	150	$2	12/31/2023
Massmutual Trust Co. FSB ADV	58	$1	03/31/2024
AMBC	58	$1	03/31/2024
Capital Advisors Ltd. LLC	55	$1	03/31/2024
AMBC	55	$1	03/31/2024
Lee Financial Co	36	$1	12/31/2023
AMBC	36	$1	12/31/2023
Parallel Advisors LLC	84	$1	12/31/2023
AMBC	84	$1	12/31/2023
Farmers & Merchants Investments Inc.	31	$0	03/31/2024
AMBC	31	$0	03/31/2024
Versant Capital Management Inc	19	$0	03/31/2024
AMBC	19	$0	03/31/2024
Proequities Inc.		$0	12/31/2023
Put	0	$0	12/31/2023
AMBC	0	$0	12/31/2023
Call	0	$0	12/31/2023
Robeco Institutional Asset Management B.V.	0	$0	12/31/2023
AMBC	0	$0	12/31/2023
Parkside Financial Bank & Trust	13	$0	12/31/2023
AMBC	13	$0	12/31/2023
Allworth Financial LP	24	$0	12/31/2023
AMBC	24	$0	12/31/2023
Farther Finance Advisors LLC	2	$0	12/31/2023
AMBC	2	$0	12/31/2023
Belvedere Trading LLC	21,266	$-243	12/31/2023
Put	36,000	$593	12/31/2023
AMBC	21,266	$350	12/31/2023