# EDGAR Filing Document

**Accession Number:** 0001096978
**File Stem:** 0001096978-26-000004
**Filing Date:** 2026-2
**Character Count:** 14938
**Document Hash:** a7ee5f06ec96d154d6f303eff34a6afd
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001096978-26-000004.hdr.sgml**: 20260225

**ACCESSION NUMBER**: 0001096978-26-000004

**CONFORMED SUBMISSION TYPE**: 13F-HR

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260225

**DATE AS OF CHANGE**: 20260225

**EFFECTIVENESS DATE**: 20260225

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MARINER INVESTMENT GROUP LLC
- **CENTRAL INDEX KEY:** 0001096978

**ORGANIZATION NAME:**
- **EIN:** 510661527
- **STATE OF INCORPORATION:** DE

**FILING VALUES:**
- **FORM TYPE:** 13F-HR
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 028-11231
- **FILM NUMBER:** 26676404

**BUSINESS ADDRESS:**
- **STREET 1:** 500 MAMARONECK AVENUE, 4TH FLOOR
- **CITY:** HARRISON
- **STATE:** NY
- **ZIP:** 10528
- **BUSINESS PHONE:** 914-670-4300

**MAIL ADDRESS:**
- **STREET 1:** 500 MAMARONECK AVENUE, 4TH FLOOR
- **CITY:** HARRISON
- **STATE:** NY
- **ZIP:** 10528

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** MARINER INVESTMENT GROUP INC
- **DATE OF NAME CHANGE:** 19991015

### FORM 13F COVER PAGE

**Report for the Calendar Year or Quarter Ended:** 12-31-2025

**Check here if Amendment** [ ] **Amendment Number:** 

**This Amendment (Check only one.):** [ ] is a restatement.

[ ] adds new holdings entries.

**Institutional Investment Manager Filing this Report:**

**Name:** MARINER INVESTMENT GROUP LLC<br>**Address:** 500 MAMARONECK AVENUE 4TH FLOOR<br>Harrison, NY 10528

**Form 13F File Number:** 028-11231

**CRD Number (if applicable):** 000124744

**SEC File Number (if applicable):** 801-62016

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.

**Person Signing this Report on Behalf of Reporting Manager:**

**Name:** Patrick Beirne<br>**Title:** Chief Operating Officer<br>**Phone:** 914-670-4342

**Signature, Place, and Date of Signing:**

/s/  Patrick Beirne  New York, NY  02-17-2026<br>[Signature]  [City, State]  [Date]

**Report Type (Check only one.):**

[x] **13F HOLDINGS REPORT.** (Check here if all holdings of this reporting manager are reported in this report.)

[ ] **13F NOTICE.** (Check here if no holdings are reported in this report, and all holdings are reported by other reporting manager(s).)

[ ] **13F COMBINATION REPORT.** (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)

### Form 13F Summary Page

**Report Summary:**

**Number of Other Included Managers:** 0

**Form 13F Information Table Entry Total:** 111

**Form 13F Information Table Value Total:** $1712737524

      (round to nearest dollar)

**List of Other Included Managers:**

Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.

[If there are no entries in this list, state “NONE” and omit the column headings and list entries.]

**NONE**

### FORM 13F INFORMATION TABLE

---

|  |  |  |  |  |  |  |  |  |  |  |  |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| NAME OF ISSUER | TITLE OF CLASS | CUSIP | FIGI | VALUE (x$1000) | SHRS OR PRN AMT | SH/PRN | PUT/CALL | INVESTMENT DISCRETION | OTHER MANAGER | VOTING AUTHORITY | VOTING AUTHORITY | VOTING AUTHORITY |
| NAME OF ISSUER | TITLE OF CLASS | CUSIP | FIGI | VALUE (x$1000) | SHRS OR PRN AMT | SH/PRN | PUT/CALL | INVESTMENT DISCRETION | OTHER MANAGER | SOLE | SHARED | NONE |
| ALIBABA GROUP HLDG LTD | NOTE 0.500% 6/0 | 01609WBG6 |  | 23332500 | 15000000 | PRN |  | DFND |  | 15000000 | 0 | 0 |
| ALPHABET INC | CAP STK CL C | 02079K107 |  | 109830000 | 350000 | SH |  | DFND |  | 350000 | 0 | 0 |
| ANTERO RESOURCES CORP | COM | 03674X106 |  | 1326710 | 38500 | SH |  | DFND |  | 38500 | 0 | 0 |
| APPLE INC | COM | 037833100 |  | 67421280 | 248000 | SH |  | DFND |  | 248000 | 0 | 0 |
| ASML HOLDING N V | N Y REGISTRY SHS | N07059210 |  | 99496980 | 93000 | SH |  | DFND |  | 93000 | 0 | 0 |
| BLACKSTONE SECD LENDING FD | COMMON STOCK | 09261X102 |  | 43750 | 125000 | SH | Put | DFND |  | 125000 | 0 | 0 |
| BOLT PROJS HLDGS INC | *W EXP 08/13/202 | 09769B115 |  | 317 | 19150 | SH |  | DFND |  | 19150 | 0 | 0 |
| BOREALIS FOODS INC | *W EXP 02/07/202 | 09973D113 |  | 1167 | 23300 | SH |  | DFND |  | 23300 | 0 | 0 |
| BROADCOM INC | COM | 11135F101 |  | 180750 | 10000 | SH | Call | DFND |  | 10000 | 0 | 0 |
| BUILDERS FIRSTSOURCE INC | COM | 12008R107 |  | 237500 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| CARRIER GLOBAL CORPORATION | COM | 14448C104 |  | 125000 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| CATERPILLAR INC | COM | 149123101 |  | 210000 | 40000 | SH | Call | DFND |  | 40000 | 0 | 0 |
| CHEMOURS CO | COM | 163851108 |  | 648450 | 55000 | SH |  | DFND |  | 55000 | 0 | 0 |
| CHEMOURS CO | COM | 163851108 |  | 2500 | 50000 | SH | Call | DFND |  | 50000 | 0 | 0 |
| CHIMERA INVT CORP | COM SHS | 16934Q802 |  | 3604700 | 290000 | SH |  | DFND |  | 290000 | 0 | 0 |
| CINTAS CORP | COM | 172908105 |  | 50590830 | 269000 | SH |  | DFND |  | 269000 | 0 | 0 |
| CISCO SYS INC | COM | 17275R102 |  | 105685160 | 1372000 | SH |  | DFND |  | 1372000 | 0 | 0 |
| COGENT COMMUNICATIONS HLDGS | COM NEW | 19239V302 |  | 477750 | 105000 | SH | Put | DFND |  | 105000 | 0 | 0 |
| COMCAST CORP NEW | CL A | 20030N101 |  | 1270325 | 42500 | SH |  | DFND |  | 42500 | 0 | 0 |
| COMCAST CORP NEW | CL A | 20030N101 |  | 41400 | 120000 | SH | Put | DFND |  | 120000 | 0 | 0 |
| COMFORT SYS USA INC | COM | 199908104 |  | 1866580 | 2000 | SH |  | DFND |  | 2000 | 0 | 0 |
| CONOCOPHILLIPS | COM | 20825C104 |  | 175000 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| CONSTELLATION ENERGY CORP | COM | 21037T109 |  | 562500 | 30000 | SH | Call | DFND |  | 30000 | 0 | 0 |
| COREWEAVE INC | COM CL A | 21873S108 |  | 143220 | 2000 | SH |  | DFND |  | 2000 | 0 | 0 |
| COREWEAVE INC | COM CL A | 21873S108 |  | 3875 | 25000 | SH | Call | DFND |  | 25000 | 0 | 0 |
| CORNING INC | COM | 219350105 |  | 738000 | 200000 | SH | Call | DFND |  | 200000 | 0 | 0 |
| COSTCO WHSL CORP NEW | COM | 22160K105 |  | 107792500 | 125000 | SH |  | DFND |  | 125000 | 0 | 0 |
| CREDO TECHNOLOGY GROUP HOLDI | ORDINARY SHARES | G25457105 |  | 287780 | 2000 | SH |  | DFND |  | 2000 | 0 | 0 |
| CROWN HLDGS INC | COM | 228368106 |  | 514850 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| CYCURION INC | *W EXP 02/13/203 | 95758L115 |  | 1020 | 30000 | SH |  | DFND |  | 30000 | 0 | 0 |
| D R HORTON INC | COM | 23331A109 |  | 258300 | 61500 | SH | Put | DFND |  | 61500 | 0 | 0 |
| DELTA AIR LINES INC DEL | COM NEW | 247361702 |  | 30000 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| DOW INC | COM | 260557103 |  | 411500 | 550000 | SH | Put | DFND |  | 550000 | 0 | 0 |
| DOXIMITY INC | CL A | 26622P107 |  | 5000 | 40000 | SH | Put | DFND |  | 40000 | 0 | 0 |
| DUKE ENERGY CORP NEW | COM NEW | 26441C204 |  | 6007013 | 51250 | SH |  | DFND |  | 51250 | 0 | 0 |
| DUKE ENERGY CORP NEW | COM NEW | 26441C204 |  | 1250 | 25000 | SH | Call | DFND |  | 25000 | 0 | 0 |
| DYCOM INDS INC | COM | 267475101 |  | 1013700 | 3000 | SH |  | DFND |  | 3000 | 0 | 0 |
| EATON VANCE MUN BD FD | COM | 27827X101 |  | 118521 | 12181 | SH |  | DFND |  | 12181 | 0 | 0 |
| ENTERGY CORP NEW | COM | 29364G103 |  | 4159350 | 45000 | SH |  | DFND |  | 45000 | 0 | 0 |
| EQT CORP | COM | 26884L109 |  | 1072000 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| EXPRO GROUP HOLDINGS NV | COM | N3144W105 |  | 267000 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| FERGUSON ENTERPRISES INC | COMMON STOCK NEW | 31488V107 |  | 1335780 | 6000 | SH |  | DFND |  | 6000 | 0 | 0 |
| FLUOR CORP | NOTE 1.125% 8/1 | 343412AJ1 |  | 17239670 | 15100000 | PRN |  | DFND |  | 15100000 | 0 | 0 |
| FMC CORP | COM NEW | 302491303 |  | 66250 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| FORD MTR CO | NOTE 3/1 | 345370CZ1 |  | 20820000 | 20000000 | PRN |  | DFND |  | 20000000 | 0 | 0 |
| FS KKR CAP CORP | COM | 302635206 |  | 266250 | 425000 | SH | Put | DFND |  | 425000 | 0 | 0 |
| GRUPO AEROMEXICO SAB DE CV | SPONSORED ADS | 40054J109 |  | 3717389 | 169280 | SH |  | DFND |  | 169280 | 0 | 0 |
| HALLIBURTON CO | COM | 406216101 |  | 126000 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| HONEYWELL INTL INC | COM | 438516106 |  | 76475280 | 392000 | SH |  | DFND |  | 392000 | 0 | 0 |
| HOWMET AEROSPACE INC | COM | 443201108 |  | 18750 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| INTEL CORP | COM | 458140100 |  | 81180000 | 2200000 | SH |  | DFND |  | 2200000 | 0 | 0 |
| INTERNATIONAL PAPER CO | COM | 460146103 |  | 117500 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| INVESCO QQQ TR | UNIT SER 1 | 46090E103 |  | 66750 | 50000 | SH | Call | DFND |  | 50000 | 0 | 0 |
| ISHARES BITCOIN TRUST ETF | SHS BEN INT | 46438F101 |  | 106575512 | 2146536 | SH |  | DFND |  | 2146536 | 0 | 0 |
| ISHARES TR | 1 3 YR TREAS BD | 464287457 |  | 218314 | 2636 | SH |  | DFND |  | 2636 | 0 | 0 |
| ISHARES TR | 10+ YR INVST GRD | 464289511 |  | 20180000 | 400000 | SH |  | DFND |  | 400000 | 0 | 0 |
| ISHARES TR | EXPANDED TECH | 464287515 |  | 37500 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| ISHARES TR | IBOXX HI YD ETF | 464288513 |  | 201575 | 2500 | SH |  | DFND |  | 2500 | 0 | 0 |
| ISHARES TR | IBOXX HI YD ETF | 464288513 |  | 192710 | 1496000 | SH | Put | DFND |  | 1496000 | 0 | 0 |
| ISHARES TR | RUSSELL 2000 ETF | 464287655 |  | 90110 | 206500 | SH | Put | DFND |  | 206500 | 0 | 0 |
| KROGER CO | COM | 501044101 |  | 937200 | 15000 | SH |  | DFND |  | 15000 | 0 | 0 |
| LAM RESEARCH CORP | COM NEW | 512807306 |  | 125988480 | 736000 | SH |  | DFND |  | 736000 | 0 | 0 |
| LEGENCE CORP | CL A | 52476L109 |  | 430400 | 10000 | SH |  | DFND |  | 10000 | 0 | 0 |
| LENNAR CORP | CL A | 526057104 |  | 459225 | 58500 | SH | Put | DFND |  | 58500 | 0 | 0 |
| LINCOLN ELEC HLDGS INC | COM | 533900106 |  | 3834240 | 16000 | SH |  | DFND |  | 16000 | 0 | 0 |
| LINDE PLC | SHS | G54950103 |  | 85278000 | 200000 | SH |  | DFND |  | 200000 | 0 | 0 |
| LIVE NATION ENTERTAINMENT IN | NOTE 2.875% 1/1 | 538034BC2 |  | 5265000 | 5000000 | PRN |  | DFND |  | 5000000 | 0 | 0 |
| LIVE NATION ENTERTAINMENT IN | NOTE 3.125% 1/1 | 538034BA6 |  | 7277500 | 5000000 | PRN |  | DFND |  | 5000000 | 0 | 0 |
| LOWES COS INC | COM | 548661107 |  | 24357160 | 101000 | SH |  | DFND |  | 101000 | 0 | 0 |
| LUMEN TECHNOLOGIES INC | COM | 550241103 |  | 582750 | 75000 | SH |  | DFND |  | 75000 | 0 | 0 |
| LYONDELLBASELL INDUSTRIES N | SHS - A - | N53745100 |  | 1316000 | 500000 | SH | Put | DFND |  | 500000 | 0 | 0 |
| MARTIN MARIETTA MATLS INC | COM | 573284106 |  | 311330 | 500 | SH |  | DFND |  | 500 | 0 | 0 |
| MASTEC INC | COM | 576323109 |  | 3151865 | 14500 | SH |  | DFND |  | 14500 | 0 | 0 |
| MASTERCARD INCORPORATED | CL A | 57636Q104 |  | 57088000 | 100000 | SH |  | DFND |  | 100000 | 0 | 0 |
| MCDONALDS CORP | COM | 580135101 |  | 49817690 | 163000 | SH |  | DFND |  | 163000 | 0 | 0 |
| MICROSOFT CORP | COM | 594918104 |  | 166365280 | 344000 | SH |  | DFND |  | 344000 | 0 | 0 |
| NEXTERA ENERGY CAP HLDGS INC | NOTE 3.000% 3/0 | 65339KCY4 |  | 12435000 | 10000000 | PRN |  | DFND |  | 10000000 | 0 | 0 |
| NOBLE CORP PLC | ORD SHS A | G65431127 |  | 282400 | 10000 | SH |  | DFND |  | 10000 | 0 | 0 |
| NUVEEN FLOATING RATE INCOME | COM | 67072T108 |  | 4960211 | 633488 | SH |  | DFND |  | 633488 | 0 | 0 |
| NVIDIA CORPORATION | COM | 67066G104 |  | 92690500 | 497000 | SH |  | DFND |  | 497000 | 0 | 0 |
| OLIN CORP | COM PAR $1 | 680665205 |  | 362500 | 200000 | SH | Put | DFND |  | 200000 | 0 | 0 |
| ON SEMICONDUCTOR CORP | NOTE 0.500% 3/0 | 682189AU9 |  | 9485000 | 10000000 | PRN |  | DFND |  | 10000000 | 0 | 0 |
| ONEOK INC NEW | COM | 682680103 |  | 127500 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| PENNYMAC CORP | NOTE 8.500% 6/0 | 70932AAH6 |  | 1063000 | 1000000 | PRN |  | DFND |  | 1000000 | 0 | 0 |
| POST HLDGS INC | COM | 737446104 |  | 225000 | 75000 | SH | Put | DFND |  | 75000 | 0 | 0 |
| RANGE RES CORP | COM | 75281A109 |  | 1621960 | 46000 | SH |  | DFND |  | 46000 | 0 | 0 |
| RANGE RES CORP | COM | 75281A109 |  | 91000 | 130000 | SH | Call | DFND |  | 130000 | 0 | 0 |
| REDFIN CORP | NOTE 0.500% 4/0 | 75737FAE8 |  | 1547945 | 1645000 | PRN |  | DFND |  | 1645000 | 0 | 0 |
| REDWOOD TRUST INC | COM | 758075402 |  | 4121763 | 745346 | SH |  | DFND |  | 745346 | 0 | 0 |
| REDWOOD TRUST INC | NOTE 7.750% 6/1 | 758075AF2 |  | 1795500 | 1800000 | PRN |  | DFND |  | 1800000 | 0 | 0 |
| RITHM CAPITAL CORP | COM NEW | 64828T201 |  | 9468950 | 868711 | SH |  | DFND |  | 868711 | 0 | 0 |
| SHIFT4 PMTS INC | CL A | 82452J109 |  | 7871250 | 125000 | SH |  | DFND |  | 125000 | 0 | 0 |
| SMURFIT WESTROCK PLC | SHS | G8267P108 |  | 40000 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| SNOWFLAKE INC | NOTE 10/0 | 833445AB5 |  | 7435000 | 5000000 | PRN |  | DFND |  | 5000000 | 0 | 0 |
| SPDR S 500 ETF TR | TR UNIT | 78462F103 |  | 0 | 0 | SH |  | DFND |  | 0 | 0 | 0 |
| SPDR S 500 ETF TR | TR UNIT | 78462F103 |  | 39250 | 50000 | SH | Call | DFND |  | 50000 | 0 | 0 |
| SPDR S 500 ETF TR | TR UNIT | 78462F103 |  | 53625 | 75000 | SH | Put | DFND |  | 75000 | 0 | 0 |
| TALEN ENERGY CORP | COM | 87422Q109 |  | 1874200 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| TELEPHONE  DATA SYS INC | COM NEW | 879433829 |  | 205000 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| TEXAS INSTRS INC | COM | 882508104 |  | 96980910 | 559000 | SH |  | DFND |  | 559000 | 0 | 0 |
| UNITED AIRLS HLDGS INC | COM | 910047109 |  | 64125 | 75000 | SH | Put | DFND |  | 75000 | 0 | 0 |
| VALMONT INDS INC | COM | 920253101 |  | 804640 | 2000 | SH |  | DFND |  | 2000 | 0 | 0 |
| VERTIV HOLDINGS CO | COM CL A | 92537N108 |  | 663750 | 75000 | SH | Call | DFND |  | 75000 | 0 | 0 |
| VISTRA CORP | COM | 92840M102 |  | 806650 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| VISTRA CORP | COM | 92840M102 |  | 196875 | 35000 | SH | Call | DFND |  | 35000 | 0 | 0 |
| VULCAN MATLS CO | COM | 929160109 |  | 285220 | 1000 | SH |  | DFND |  | 1000 | 0 | 0 |
| WILLIAMS COS INC | COM | 969457100 |  | 2704950 | 45000 | SH |  | DFND |  | 45000 | 0 | 0 |
| WILLIAMS COS INC | COM | 969457100 |  | 125000 | 150000 | SH | Call | DFND |  | 150000 | 0 | 0 |
| WOLFSPEED INC | COMMON STOCK | 97785W106 |  | 348200 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| WOLFSPEED INC | NOTE 2.500% 6/1 | 977852AP7 |  | 402774 | 271000 | PRN |  | DFND |  | 271000 | 0 | 0 |
| WORTHINGTON ENTERPRISES INC | COM | 981811102 |  | 216388 | 4196 | SH |  | DFND |  | 4196 | 0 | 0 |

---