Ambac Financial Group, Inc.

Historical 13F Holders

Symbol
OSG
CUSIP
023139884
All holders as of
Q2 2026
Type
Equity
Class
COM NEW
Reported Value, Excluding Options
Total Filings

13D/G Filers

Investors who own more than 5% of a class must file a Schedule 13D or 13G. Each filer's latest filing for 023139884 since 12/18/2024, largest first.

Filer % of Class Filed
BlackRock, Inc. 13G/A 7.6% 10/17/2025
Event 9/30/2025
Vanguard Capital Management LLC 13G 5.0% 7/31/2026
Event 6/30/2026
Under 5%, checked the "5 percent or less" box, or amended by a later filing (5)
Western Standard LLC 13G/A 4.99% 5/11/2026
Event 3/31/2026
Dimensional Fund Advisors LP 13G/A 4.6% 10/9/2025
Event 9/30/2025
Susquehanna Securities, LLC 13G/A
2.2% 11/13/2025
Event 9/30/2025
Jane Street Group, LLC 13G/A
1.7% 5/11/2026
Event 3/31/2026
Vanguard Group Inc 13G/A 0% 3/27/2026
Event 3/13/2026

13F Holders by Quarter

Period Filings Shares, Excl. Options Value, Excl. Options
2026 Q3 2 10.6 k $44.0 k
2026 Q2 158 30.1 M $188 M
2026 Q1 157 32.5 M $151 M
2025 Q4 162 34.8 M $271 M
2025 Q3 150 37.7 M $540 M
2025 Q2 164 37.4 M $265 M
2025 Q1 196 37.6 M $328 M
2024 Q4 199 41.5 M $522 M
2024 Q3 197 40.5 M $453 M
2024 Q2 199 39.4 M $505 M
2024 Q1 186 39.1 M $611 M
2023 Q4 189 39.4 M $649 M
2023 Q3 177 36.3 M $439 M
2023 Q2 173 37.2 M $530 M
2023 Q1 174 39.0 M $598 M
2022 Q4 181 36.2 M $630 M
2022 Q3 170 31.6 M $403 M
2022 Q2 154 37.0 M $419 M
2022 Q1 170 37.8 M $392 M
2021 Q4 154 38.1 M $612 M
2021 Q3 150 36.1 M $516 M
2021 Q2 140 36.1 M $565 M
2021 Q1 156 36.5 M $612 M
2020 Q4 170 39.3 M $604 M
2020 Q3 150 36.7 M $469 M
2020 Q2 153 37.4 M $535 M
2020 Q1 146 36.2 M $448 M
2019 Q4 148 37.3 M $804 M
2019 Q3 141 36.0 M $704 M
2019 Q2 160 38.3 M $644 M
2019 Q1 175 36.5 M $662 M
2018 Q4 168 38.8 M $669 M
2018 Q3 177 35.9 M $734 M
2018 Q2 167 37.1 M $735 M
2018 Q1 136 34.7 M $544 M
2017 Q4 136 34.0 M $544 M
2017 Q3 140 32.0 M $552 M
2017 Q2 148 33.2 M $575 M
2017 Q1 167 33.6 M $633 M
2016 Q4 172 33.1 M $746 M
2016 Q3 128 32.1 M $590 M
2016 Q2 133 32.6 M $537 M
2016 Q1 124 32.2 M $508 M
2015 Q4 136 34.1 M $481 M
2015 Q3 135 34.6 M $501 M
2015 Q2 137 34.8 M $579 M
2015 Q1 135 34.2 M $834 M
2014 Q4 140 33.1 M $818 M
2014 Q3 139 34.7 M $773 M
2014 Q2 144 36.4 M $1.00 B
2014 Q1 155 35.8 M $1.12 B