Octave Specialty Group, Inc.
MX ˙ BMV ˙ US0231398845
SecurityMX:OSG / Octave Specialty Group, Inc.
InstitutionCentiva Capital, LP
Latest Disclosed Ownership16,085 shares
Latest Disclosed Value $ 74,795
Centiva Capital, LP ownership in OSG / Octave Specialty Group, Inc.

On May 14, 2026 - Centiva Capital, LP filed a 13F-HR form disclosing ownership of 16,085 shares of Octave Specialty Group, Inc. (MX:OSG) valued at $74,795 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 14, 2025 disclosing 0 shares of Octave Specialty Group, Inc..

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.

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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)
2026-05-14 2026-03-31 13F OCTAVE SPECIALTY GROUP COM NEW 023139884 16,085 16,085 75 0.0006
2025-11-14 2025-09-30 13F AMBAC FINL GROUP COM NEW 023139884 0 -46,815 -100.00 0 -100.00
2025-08-13 2025-06-30 13F AMBAC FINL GROUP COM NEW 023139884 46,815 46,815 332 0.0054
2025-05-15 2025-03-31 13F AMBAC FINL GROUP COM NEW 023139884 0 -35,111 -100.00 0 -100.00
2025-02-14 2024-12-31 13F AMBAC FINL GROUP COM NEW 023139884 35,111 -9,826 -21.87 444 -11.73 0.0092
2024-11-14 2024-09-30 13F AMBAC FINL GROUP COM NEW 023139884 44,937 31,047 223.52 504 182.58 0.0099
2024-08-14 2024-06-30 13F AMBAC FINL GROUP COM NEW 023139884 13,890 -6,110 -30.55 178 -42.95 0.0030
2024-05-15 2024-03-31 13F AMBAC FINL GROUP COM NEW 023139884 20,000 20,000 313 0.0076
2022-02-14 2021-12-31 13F AMBAC FINL GROUP COM NEW 023139884 0 -89,516 -100.00 0 -100.00
2021-11-17 2021-09-30 13F/A-1 AMBAC FINL GROUP COM NEW 023139884 89,516 89,516 1,282 0.0806
2021-11-15 2021-09-30 13F AMBAC FINL GROUP COM NEW 023139884 89,516 89,516 1,282 0.0803
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.