Octave Specialty Group, Inc.
US ˙ NYSE ˙ US0231398845
DETTE SYMBOL ER IKKE LÆNGERE AKTIVT

SecurityAMBC / Octave Specialty Group, Inc.
InstitutionPrudential Financial Inc
Latest Disclosed Ownership70,110 shares
Latest Disclosed Value $ 326,012
Prudential Financial Inc reports 29.02% increase in ownership of AMBC / Octave Specialty Group, Inc.

On May 13, 2026 - Prudential Financial Inc filed a 13F-HR form disclosing ownership of 70,110 shares of Octave Specialty Group, Inc. (US:AMBC) valued at $326,012 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 54,340 shares of Octave Specialty Group, Inc.. This represents a change in shares of 29.02% during the quarter. The current value of the position is $633,093 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

Upgrade to unlock premium data and export to Excel .

Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date
Effective
Date
Form Security Class ID Avg Price
Paid (Est)
Reported
Shares
ΔShares ΔShares
(%)
Reported
Value
(x1000)
ΔValue
(%)
Alloc
(%)
ΔAlloc ΔAlloc (%) Cost Basis
(x1000)
Unrealized
Gain/Loss
(x1000)
2026-05-13 2026-03-31 13F CTAVE SPECIALTY GROUP COM NEW 023139884 70,110 15,770 29.02 326 -22.75 0.0002
2026-02-13 2025-12-31 13F OCTAVE SPECIALTY GROUP COM NEW 023139884 54,340 -2,285 -4.04 423 -10.59 0.0005
2025-11-13 2025-09-30 13F AMBAC FINL GROUP COM NEW 023139884 56,625 56,625 472 0.0006
2025-05-13 2025-03-31 13F AMBAC FINL GROUP COM NEW 023139884 0 -47,670 -100.00 0 -100.00
2025-02-11 2024-12-31 13F AMBAC FINL GROUP COM NEW 023139884 47,670 -124,000 -72.23 603 -68.66 0.0008
2024-11-14 2024-09-30 13F AMBAC FINL GROUP COM NEW 023139884 171,670 -180,200 -51.21 1,924 -57.34 0.0027
2024-08-13 2024-06-30 13F AMBAC FINL GROUP COM NEW 023139884 351,870 -251,250 -41.66 4,511 -52.15 0.0068
2024-05-14 2024-03-31 13F AMBAC FINL GROUP COM NEW 023139884 603,120 -127,000 -17.39 9,427 -21.66 0.0133
2024-02-13 2023-12-31 13F AMBAC FINL GROUP COM NEW 023139884 730,120 494,058 209.29 12,032 322.77 0.0182
2023-11-13 2023-09-30 13F AMBAC FINL GROUP COM NEW 023139884 236,062 20,000 9.26 2,847 -7.48 0.0045
2023-08-11 2023-06-30 13F AMBAC FINL GROUP COM NEW 023139884 216,062 139,640 182.72 3,077 160.02 0.0045
2023-05-12 2023-03-31 13F AMBAC FINL GROUP COM NEW 023139884 76,422 4,030 5.57 1,183 -6.26 0.0019
2023-02-14 2022-12-31 13F AMBAC FINL GROUP COM NEW 023139884 72,392 27,320 60.61 1,263 119.48 0.0021
2022-11-04 2022-09-30 13F AMBAC FINL GROUP COM NEW 023139884 45,072 -450 -0.99 575 11.22 0.0010
2022-08-15 2022-06-30 13F AMBAC FINL GROUP COM NEW 023139884 45,522 -2,250 -4.71 517 4.02 0.0008
2022-05-13 2022-03-31 13F AMBAC FINL GROUP COM NEW 023139884 47,772 -600 -1.24 497 -35.95 0.0007
2022-02-14 2021-12-31 13F AMBAC FINL GROUP COM NEW 023139884 48,372 -712 -1.45 776 10.38 0.0010
2021-11-15 2021-09-30 13F AMBAC FINL GROUP COM NEW 023139884 49,084 857 1.78 703 -6.89 0.0010
2021-08-16 2021-06-30 13F AMBAC FINL GROUP COM NEW 023139884 48,227 -3,013 -5.88 755 -12.00 0.0010
2021-05-12 2021-03-31 13F AMBAC FINL GROUP COM NEW 023139884 51,240 -902 -1.73 858 6.98 0.0013
2021-08-16 2020-12-31 13F/A-1 AMBAC FINL GROUP COM NEW 0015 023139884 52,142 -13,115 -20.10 802 -3.72 0.0013
2021-02-16 2020-12-31 13F AMBAC FINL GROUP COM NEW 023139884 52,142 -13,115 802 0.0013
2020-11-16 2020-09-30 13F AMBAC FINL GROUP COM NEW 023139884 65,257 11,949 22.42 833 9.17 0.0016
2020-08-12 2020-06-30 13F AMBAC FINL GROUP COM NEW 023139884 53,308 -16,187 -23.29 763 -11.07 0.0015
2020-05-12 2020-03-31 13F AMBAC FINL GROUP COM NEW 023139884 69,495 -1,489 -2.10 858 -43.96 0.0019
2020-02-11 2019-12-31 13F AMBAC FINL GROUP COM NEW 023139884 70,984 769 1.10 1,531 11.51 0.0023
2019-11-13 2019-09-30 13F AMBAC FINL GROUP COM NEW 023139884 70,215 -2,813 -3.85 1,373 11.54 0.0022
2019-08-08 2019-06-30 13F AMBAC FINL GROUP COM NEW 023139884 73,028 -90 -0.12 1,231 -7.09 0.0019
2019-05-15 2019-03-31 13F AMBAC FINL GROUP COM NEW 023139884 73,118 -21,604 -22.81 1,325 -18.86 0.0022
2019-02-07 2018-12-31 13F AMBAC FINL GROUP COM NEW 023139884 94,722 20,847 28.22 1,633 8.22 0.0029
2018-11-07 2018-09-30 13F AMBAC FINL GROUP COM NEW 023139884 73,875 -34,370 -31.75 1,509 -29.78 0.0022
2018-08-13 2018-06-30 13F AMBAC FINL GROUP COM NEW 023139884 108,245 108,245 2,149 0.0032
2018-05-04 2018-03-31 13F AMBAC FINL GROUP COM NEW 023139884 0 -31,704 -100.00 0 -100.00
2018-02-13 2017-12-31 13F AMBAC FINL GROUP COM NEW 023139884 31,704 -82,306 -72.19 507 -74.24 0.0007
2017-11-30 2017-09-30 13F/A-1 AMBAC FINL GROUP COM NEW 023139884 114,010 36,590 47.26 1,968 46.54 0.0215
2017-08-07 2017-06-30 13F AMBAC FINL GROUP COM NEW 023139884 77,420 3,130 4.21 1,343 -4.14 0.0020
2017-05-10 2017-03-31 13F AMBAC FINL GROUP COM NEW 023139884 74,290 10 0.01 1,401 -16.16 0.0022
2017-02-07 2016-12-31 13F AMBAC FINL GROUP COM NEW 023139884 74,280 -31,700 -29.91 1,671 -14.26 0.0027
2016-11-04 2016-09-30 13F AMBAC FINL GROUP COM NEW 023139884 105,980 11,780 12.51 1,949 25.66 0.0032
2016-08-09 2016-06-30 13F AMBAC FINL GROUP COM NEW 023139884 94,200 -500 -0.53 1,551 3.68 0.0026
2016-05-09 2016-03-31 13F AMBAC FINL GROUP COM NEW 023139884 94,700 27,100 40.09 1,496 57.14 0.0027
2016-02-12 2015-12-31 13F AMBAC FINL GROUP COM NEW 023139884 67,600 1,000 1.50 952 -1.24 0.0017
2015-11-10 2015-09-30 13F AMBAC FINL GROUP COM NEW 023139884 66,600 66,600 0.00 964 0.0019
2015-08-06 2015-06-30 13F AMBAC FINL GROUP COM NEW 023139884 0 -137,800 -100.00 0 -100.00
2015-05-01 2015-03-31 13F AMBAC FINL GROUP COM NEW 023139884 137,800 137,800 3,335 0.0058
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.