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

SecurityAMBC / Octave Specialty Group, Inc.
InstitutionQuantbot Technologies LP
Latest Disclosed Ownership38,708 shares
Latest Disclosed Value $ 179,992
Quantbot Technologies LP reports 101.17% increase in ownership of AMBC / Octave Specialty Group, Inc.

On May 13, 2026 - Quantbot Technologies LP filed a 13F-HR form disclosing ownership of 38,708 shares of Octave Specialty Group, Inc. (US:AMBC) valued at $179,992 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 10, 2026 disclosing 19,241 shares of Octave Specialty Group, Inc.. This represents a change in shares of 101.17% during the quarter. The current value of the position is $349,533 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 OCTAVE SPECIALTY GROUP COM 023139884 38,708 19,467 101.17 180 20.13 0.0074
2026-02-10 2025-12-31 13F OCTAVE SPECIALTY GROUP COM 023139884 19,241 19,241 150 0.0050
2025-11-12 2025-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 0 -18,834 -100.00 0 -100.00
2025-08-13 2025-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 18,834 -81,474 -81.22 134 -84.83 0.0034
2025-05-13 2025-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 100,308 59,874 148.08 878 71.62 0.0279
2025-02-11 2024-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 40,434 -9,465 -18.97 511 -8.59 0.0187
2024-11-13 2024-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 49,899 16,375 48.85 559 30.30 0.0221
2024-08-09 2024-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 33,524 33,524 430 0.0208
2024-02-14 2023-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -2,739 -100.00 0 -100.00
2023-11-07 2023-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 2,739 -4,534 -62.34 33 -67.96 0.0022
2023-08-08 2023-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 7,273 7,273 104 0.0068
2023-05-12 2023-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -21,433 -100.00 0 -100.00
2023-02-13 2022-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 21,433 21,433 374 0.0268
2021-02-12 2020-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -229 -100.00 0 -100.00
2020-11-16 2020-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 229 37 19.27 2 0.00 0.0002
2020-08-13 2020-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 192 192 2 0.0003
2020-02-10 2019-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -531 -100.00 0 -100.00
2019-11-12 2019-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 531 531 10 0.0010
2019-05-13 2019-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -960 -100.00 0 -100.00
2019-02-13 2018-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 960 -2,603 -73.06 16 -77.78 0.0016
2018-11-13 2018-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 3,563 3,563 72 0.0050
2018-08-13 2018-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 0 -800 -100.00 0 -100.00
2018-05-11 2018-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 800 800 12 0.0010
2016-04-28 2016-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 0 0 0.0000
2015-10-22 2015-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 0 0 0 0.0000
2015-07-27 2015-06-30 13F AMBAC FINANCIAL GROUP COM 023139884 0 -7,665 -100.00 0 -100.00
2015-04-24 2015-03-31 13F AMBAC FINANCIAL GROUP COM 023139884 7,665 7,665 185 0.0458
2015-01-27 2014-12-31 13F AMBAC FINANCIAL GROUP COM 023139884 0 -3,339 -100.00 0 -100.00
2014-10-15 2014-09-30 13F AMBAC FINANCIAL GROUP COM 023139884 3,339 3,339 73 0.0100
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.