Form 13-F position report

AMBAC FINL GROUP INC NEW COM S

Reported by MARSHALL WACE LLP

OSG CUSIP 023139884 Manager CIK 0001318757

Reported 455,074 shares, down 193,081 (29.8%) from the prior quarter.

Reported value -17.5%; share count -29.8% vs. the prior quarter.

Reduced
% of reported 13F value < 0.01% This manager · Q3 2025
Shares 455,074 Quarter-end amount reported
Reported value $3,795,318 Fair value at quarter end
Consecutive quarters held 7 Through Q3 2025

Reported position value by quarter

Reported position value by quarter

Each bar is a Form 13-F quarter-end snapshot. It does not show trades made within the quarter.

Reported position value by quarter
Date Holding Value
2022-12-31 1151545
2023-03-31 0
2023-06-30 404844
2023-09-30 0
2024-03-31 1086363
2024-06-30 4432067
2024-09-30 4086873
2024-12-31 3376779
2025-03-31 1797295
2025-06-30 4601901
2025-09-30 3795318
2025-12-31 5823892
2026-03-31 4953807
2026-06-30 3755206

Quarterly position history

How this manager's reported quarter-end position changed over time.

14 quarters
Quarterly reported position history for AMBAC FINL GROUP INC NEW COM S held by MARSHALL WACE LLP.
Quarter Activity Shares Change % of reported 13F Reported value Filed Source filing
Q2 2026 Reduced 601,796 -463,539 (-43.5%) < 0.01% $3,755,206 2026-08-13
Q1 2026 Added 1,065,335 +316,763 (42.3%) < 0.01% $4,953,807 2026-05-15
Q4 2025 Added 748,572 +293,498 (64.5%) < 0.01% $5,823,892 2026-02-13
Q3 2025 Reduced 455,074 -193,081 (-29.8%) < 0.01% $3,795,318 2025-11-13
Q2 2025 Added 648,155 +442,750 (215.5%) < 0.01% $4,601,901 2025-08-13
Q1 2025 Reduced 205,405 -61,534 (-23.1%) < 0.01% $1,797,295 2025-05-15
Q4 2024 Reduced 266,939 -97,635 (-26.8%) < 0.01% $3,376,779 2025-02-13
Q3 2024 Added 364,574 +18,859 (5.5%) < 0.01% $4,086,873 2024-11-14
Q2 2024 Added 345,715 +276,210 (397.4%) < 0.01% $4,432,067 2024-08-14
Q1 2024 New 69,505 +69,505 (0.0%) < 0.01% $1,086,363 2024-05-15
Q3 2023 Reduced 0 -28,430 (-100.0%) 0 $0 2023-11-14
Q2 2023 New 28,430 +28,430 (0.0%) < 0.01% $404,844 2023-08-14
Q1 2023 Reduced 0 -66,029 (-100.0%) 0 $0 2023-05-15
Q4 2022 New 66,029 +66,029 (0.0%) < 0.01% $1,151,545 2023-02-14

Who else reported the position

166 managers reported AMBAC FINL GROUP INC NEW COM S for Q3 2025.

Managers reporting AMBAC FINL GROUP INC NEW COM S in Q3 2025.
Manager Activity Shares Change % of reported 13F Reported value Tenure
MANUFACTURERS LIFE INSURANCE COMPANY THE Added 1,206,350 +1,188,357 0.19% $232,005,166 49 qtrs
BlackRock Inc Reduced 4,493,331 -94,723 < 0.01% $37,474,381 5 qtrs
Western Standard LLC New 2,641,351 +2,641,351 6.53% $22,028,867 5 qtrs
VANGUARD GROUP INC Reduced 2,555,181 -13,259 < 0.01% $21,310,209 50 qtrs
DIMENSIONAL FUND ADVISORS LP Reduced 2,141,047 -254,690 < 0.01% $17,860,855 48 qtrs
CONTINENTAL GENERAL INSURANCE CO Added 2,068,349 +850,000 3.34% $17,250,031 2 qtrs
GENDELL JEFFREY L Added 1,864,512 +666,092 0.29% $15,550,030 12 qtrs
FMR LLC Reduced 1,525,423 -7,222 < 0.01% $12,722,027 50 qtrs
Wolf Hill Capital Management LP Added 1,158,197 +464,753 0.89% $9,659,363 4 qtrs
Caption Management LLC Added 1,121,179 +945,105 0.07% $9,350,633 13 qtrs
Premium adds each manager's conviction percentile across reporting peers.
Filing details and methodology As reported
Report period
September 30, 2025
Filed
November 13, 2025
Filing type
13F-HR
Position type
COMMON STOCK

Voting authority reported

Sole
0
Shared
455,074
None
0

“None” means the manager reported no voting authority for those shares on non-routine matters. It does not disclose why and is not evidence of securities lending.

Form 13-F is a delayed quarter-end snapshot of disclosed long Section 13(f) securities. It can be filed up to 45 days after quarter end, excludes short positions and most non-U.S. securities, and does not reveal intra-quarter trading. For options, reported shares and value describe the underlying-share exposure; strike, expiry, premium, and written positions are not disclosed.