Form 13-F position report

AMBAC FINL GROUP INC NEW COM S

Reported by DIMENSIONAL FUND ADVISORS LP

OSG CUSIP 023139884 Manager CIK 0000354204

Reported 2,141,047 shares, down 254,690 (10.6%) from the prior quarter.

Reported value 5.0%; share count -10.6% vs. the prior quarter.

Reduced
% of reported 13F value < 0.01% This manager · Q3 2025
Shares 2,141,047 Quarter-end amount reported
Reported value $17,860,855 Fair value at quarter end
Consecutive quarters held 48 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
2021-09-30 19499000
2021-12-31 23676000
2022-03-31 16288000
2022-06-30 17727000
2022-09-30 18880000
2022-12-31 26551000
2023-03-31 26174177
2023-06-30 30919138
2023-09-30 30608159
2023-12-31 42908464
2024-03-31 44793767
2024-06-30 37856947
2024-09-30 31437294
2024-12-31 34232223
2025-03-31 22372039
2025-06-30 17009625
2025-09-30 17860855
2025-12-31 13114300
2026-03-31 6092068
2026-06-30 4474177

Quarterly position history

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

20 quarters
Quarterly reported position history for AMBAC FINL GROUP INC NEW COM S held by DIMENSIONAL FUND ADVISORS LP.
Quarter Activity Shares Change % of reported 13F Reported value Filed Source filing
Q2 2026 Reduced 716,947 -593,185 (-45.3%) < 0.01% $4,474,177 2026-08-11
Q1 2026 Reduced 1,310,132 -375,495 (-22.3%) < 0.01% $6,092,068 2026-05-07
Q4 2025 Reduced 1,685,627 -455,420 (-21.3%) < 0.01% $13,114,300 2026-02-12
Q3 2025 Reduced 2,141,047 -254,690 (-10.6%) < 0.01% $17,860,855 2025-11-12
Q2 2025 Reduced 2,395,737 -161,143 (-6.3%) < 0.01% $17,009,625 2025-08-12
Q1 2025 Reduced 2,556,880 -149,271 (-5.5%) < 0.01% $22,372,039 2025-05-13
Q4 2024 Reduced 2,706,151 -98,249 (-3.5%) < 0.01% $34,232,223 2025-02-13
Q3 2024 Reduced 2,804,400 -148,561 (-5.0%) < 0.01% $31,437,294 2024-11-07
Q2 2024 Added 2,952,961 +87,077 (3.0%) < 0.01% $37,856,947 2024-08-09
Q1 2024 Added 2,865,884 +262,205 (10.1%) 0.01% $44,793,767 2024-05-10
Q4 2023 Added 2,603,679 +65,733 (2.6%) 0.01% $42,908,464 2024-02-07
Q3 2023 Added 2,537,946 +366,605 (16.9%) 0.01% $30,608,159 2023-11-09
Q2 2023 Added 2,171,341 +480,450 (28.4%) < 0.01% $30,919,138 2023-08-09
Q1 2023 Added 1,690,891 +168,422 (11.1%) < 0.01% $26,174,177 2023-05-12
Q4 2022 Added 1,522,469 +41,660 (2.8%) < 0.01% $26,551,000 2023-02-09
Q3 2022 Reduced 1,480,809 -81,148 (-5.2%) < 0.01% $18,880,000 2022-11-10
Q2 2022 Reduced 1,561,957 -4,302 (-0.3%) < 0.01% $17,727,000 2022-08-12
Q1 2022 Added 1,566,259 +91,106 (6.2%) < 0.01% $16,288,000 2022-05-13
Q4 2021 Added 1,475,153 +113,493 (8.3%) < 0.01% $23,676,000 2022-02-09
Q3 2021 Reduced 1,361,660 -314,925 (-18.8%) < 0.01% $19,499,000 2021-11-12
Five years are shown. A free account unlocks the complete reported history. Unlock full history

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 This report 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 12, 2025
Filing type
13F-HR
Position type
COM NEW

Voting authority reported

Sole
1,998,020
Shared
96,201
None
46,826

“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.