# EDGAR Filing Document

**Accession Number:** 0001096978
**File Stem:** 0001096978-26-000005
**Filing Date:** 2026-5
**Character Count:** 14700
**Document Hash:** bc090a497ddb29d6b4b9f3e473b6d2da
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001096978-26-000005.hdr.sgml**: 20260505

**ACCESSION NUMBER**: 0001096978-26-000005

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

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260331

**FILED AS OF DATE**: 20260505

**DATE AS OF CHANGE**: 20260505

**EFFECTIVENESS DATE**: 20260505

**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:** 26941055

**BUSINESS ADDRESS:**
- **STREET 1:** 299 PARK AVENUE, 5TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10171
- **BUSINESS PHONE:** 914-670-4300

**MAIL ADDRESS:**
- **STREET 1:** 299 PARK AVENUE, 5TH FLOOR
- **CITY:** NEW YORK
- **STATE:** NY
- **ZIP:** 10171

**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:** 03-31-2026

**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:** 299 PARK AVENUE 5TH FLOOR<br>NEW YORK, NY 10171

**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  05-05-2026<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:** 108

**Form 13F Information Table Value Total:** $345879159

      (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 |
| AES CORP | COM | 00130H105 |  | 493150 | 35000 | SH |  | DFND |  | 35000 | 0 | 0 |
| ALIBABA GROUP HLDG LTD | NOTE 0.500% 6/0 | 01609WBG6 |  | 34718750 | 25000000 | PRN |  | DFND |  | 25000000 | 0 | 0 |
| AMPHENOL CORP | CL A | 032095101 |  | 315000 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| ANGEL OAK MORTGAGE REIT INC | COM | 03464Y108 |  | 145938 | 17754 | SH |  | DFND |  | 17754 | 0 | 0 |
| APA CORPORATION | COM | 03743Q108 |  | 27000 | 200000 | SH | Put | DFND |  | 200000 | 0 | 0 |
| BLACKSTONE SECD LENDING FD | COMMON STOCK | 09261X102 |  | 384375 | 325000 | SH | Put | DFND |  | 325000 | 0 | 0 |
| BOREALIS FOODS INC | *W EXP 02/07/202 | 09973D113 |  | 1806 | 23300 | SH |  | DFND |  | 23300 | 0 | 0 |
| BUILDERS FIRSTSOURCE INC | COM | 12008R107 |  | 649750 | 115000 | SH | Put | DFND |  | 115000 | 0 | 0 |
| CARRIER GLOBAL CORPORATION | COM | 14448C104 |  | 124375 | 75000 | SH | Put | DFND |  | 75000 | 0 | 0 |
| CATERPILLAR INC | COM | 149123101 |  | 2692148 | 3800 | SH |  | DFND |  | 3800 | 0 | 0 |
| CATERPILLAR INC | COM | 149123101 |  | 48125 | 5000 | SH | Call | DFND |  | 5000 | 0 | 0 |
| CHIMERA INVT CORP | COM SHS | 16934Q802 |  | 4755182 | 378899 | SH |  | DFND |  | 378899 | 0 | 0 |
| COGENT COMM HOLDINGS INC | COM NEW | 19239V302 |  | 393750 | 105000 | SH | Put | DFND |  | 105000 | 0 | 0 |
| COHERENT CORP | COM | 19247G107 |  | 535500 | 42500 | SH | Call | DFND |  | 42500 | 0 | 0 |
| CONOCOPHILLIPS | COM | 20825C104 |  | 29500 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| CONSTELLATION ENERGY CORP | COM | 21037T109 |  | 19000 | 10000 | SH | Call | DFND |  | 10000 | 0 | 0 |
| CORE SCIENTIFIC INC NEW | COM | 21874A106 |  | 299200 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| CORNING INC | COM | 219350105 |  | 209250 | 30000 | SH | Call | DFND |  | 30000 | 0 | 0 |
| CPI CARD GROUP INC | COM NEW | 12634H200 |  | 261906 | 18050 | SH |  | DFND |  | 18050 | 0 | 0 |
| CROWN HLDGS INC | COM | 228368106 |  | 501250 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| CROWN HLDGS INC | COM | 228368106 |  | 16500 | 15000 | SH | Call | DFND |  | 15000 | 0 | 0 |
| CYCURION INC | *W EXP 02/13/203 | 95758L115 |  | 618 | 30000 | SH |  | DFND |  | 30000 | 0 | 0 |
| D R HORTON INC | COM | 23331A109 |  | 493300 | 107000 | SH | Put | DFND |  | 107000 | 0 | 0 |
| DEERE  CO | COM | 244199105 |  | 128500 | 10000 | SH | Put | DFND |  | 10000 | 0 | 0 |
| DELTA AIR LINES INC | COM NEW | 247361702 |  | 15875 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| DEVON ENERGY CORP NEW | COM | 25179M103 |  | 58000 | 300000 | SH | Put | DFND |  | 300000 | 0 | 0 |
| DOW HLDGS INC | COM | 260557103 |  | 69850 | 205000 | SH | Put | DFND |  | 205000 | 0 | 0 |
| DYNEX CAP INC | COM | 26817Q886 |  | 1212200 | 95000 | SH |  | DFND |  | 95000 | 0 | 0 |
| ENTEGRIS INC | COM | 29362U104 |  | 90000 | 25000 | SH | Call | DFND |  | 25000 | 0 | 0 |
| ENTERGY CORP NEW | COM | 29364G103 |  | 4494400 | 40000 | SH |  | DFND |  | 40000 | 0 | 0 |
| EQT CORP | COM | 26884L109 |  | 1272800 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| ETF SER SOLUTIONS | US GLB JETS | 26922A842 |  | 104000 | 200000 | SH | Call | DFND |  | 200000 | 0 | 0 |
| EXPRO GROUP HOLDINGS NV | COM | N3144W105 |  | 348200 | 20000 | SH |  | DFND |  | 20000 | 0 | 0 |
| FIFTH THIRD BANCORP | COM | 316773100 |  | 35625 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| FLUOR CORP | NOTE 1.125% 8/1 | 343412AJ1 |  | 31004775 | 25100000 | PRN |  | DFND |  | 25100000 | 0 | 0 |
| FS KKR CAP CORP | COM | 302635206 |  | 832500 | 700000 | SH | Put | DFND |  | 700000 | 0 | 0 |
| GLOBAL PMTS INC | NOTE 1.500% 3/0 | 37940XAU6 |  | 22076276 | 25000000 | PRN |  | DFND |  | 25000000 | 0 | 0 |
| GOLUB CAP BDC INC | COM | 38173M102 |  | 130000 | 200000 | SH | Put | DFND |  | 200000 | 0 | 0 |
| GRUPO AEROMEXICO SAB DE CV | SPONSORED ADS | 40054J109 |  | 2371613 | 169280 | SH |  | DFND |  | 169280 | 0 | 0 |
| HOWMET AEROSPACE INC | COM | 443201108 |  | 53750 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| IHEARTMEDIA INC | COM CL A | 45174J509 |  | 184480 | 63178 | SH |  | DFND |  | 63178 | 0 | 0 |
| INTERNATIONAL PAPER CO | COM | 460146103 |  | 137500 | 100000 | SH | Put | DFND |  | 100000 | 0 | 0 |
| INVESCO EXCH TRADED FD TR II | SR LN ETF | 46138G508 |  | 100000 | 1000000 | SH | Put | DFND |  | 1000000 | 0 | 0 |
| ISHARES BITCOIN TRUST ETF | SHS BEN INT | 46438F101 |  | 120229704 | 3129352 | SH |  | DFND |  | 3129352 | 0 | 0 |
| ISHARES INC | MSCI STH KOR ETF | 464286772 |  | 262500 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| ISHARES TR | 1 3 YR TREAS BD | 464287457 |  | 6260210 | 75817 | SH |  | DFND |  | 75817 | 0 | 0 |
| ISHARES TR | 3 7 YR TREAS BD | 464288661 |  | 905867 | 7638 | SH |  | DFND |  | 7638 | 0 | 0 |
| ISHARES TR | EXPANDED TECH | 464287515 |  | 1000625 | 12500 | SH |  | DFND |  | 12500 | 0 | 0 |
| ISHARES TR | IBOXX HI YD ETF | 464288513 |  | 872816 | 2121300 | SH | Put | DFND |  | 2121300 | 0 | 0 |
| ISHARES TR | US AER DEF ETF | 464288760 |  | 26000 | 10000 | SH | Put | DFND |  | 10000 | 0 | 0 |
| JEFFERIES FINANCIAL GROUP IN | COM | 47233W109 |  | 33750 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| KARMAN HLDGS INC | COMMON STOCK | 485924104 |  | 400250 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| KRAFT HEINZ CO | COM | 500754106 |  | 91000 | 200000 | SH | Put | DFND |  | 200000 | 0 | 0 |
| LEGENCE CORP | CL A | 52476L109 |  | 846900 | 15000 | SH |  | DFND |  | 15000 | 0 | 0 |
| LENNAR CORP | CL A | 526057104 |  | 551050 | 123500 | SH | Put | DFND |  | 123500 | 0 | 0 |
| LINCOLN ELEC HLDGS INC | COM | 533900106 |  | 1494480 | 6000 | SH |  | DFND |  | 6000 | 0 | 0 |
| LIVE NATION ENTERTAINMENT IN | NOTE 2.875% 1/1 | 538034BC2 |  | 5400000 | 5000000 | PRN |  | DFND |  | 5000000 | 0 | 0 |
| LIVE NATION ENTERTAINMENT IN | NOTE 3.125% 1/1 | 538034BA6 |  | 7607500 | 5000000 | PRN |  | DFND |  | 5000000 | 0 | 0 |
| LUMEN TECHNOLOGIES INC | COM | 550241103 |  | 521250 | 75000 | SH |  | DFND |  | 75000 | 0 | 0 |
| LYONDELLBASELL INDUSTRIES NV | SHS - A - | N53745100 |  | 110000 | 240000 | SH | Put | DFND |  | 240000 | 0 | 0 |
| MACOM TECH SOLUTIONS HLDGS I | COM | 55405Y100 |  | 666210 | 3000 | SH |  | DFND |  | 3000 | 0 | 0 |
| MASTEC INC | COM | 576323109 |  | 1930440 | 6000 | SH |  | DFND |  | 6000 | 0 | 0 |
| MCDONALDS CORP | COM | 580135101 |  | 26700 | 30000 | SH | Call | DFND |  | 30000 | 0 | 0 |
| MFA FINL INC | COM | 55272X607 |  | 2011800 | 210000 | SH |  | DFND |  | 210000 | 0 | 0 |
| MICROCHIP TECHNOLOGY INC. | COM | 595017104 |  | 839930 | 13000 | SH |  | DFND |  | 13000 | 0 | 0 |
| NOBLE CORP PLC | ORD SHS A | G65431127 |  | 490700 | 10000 | SH |  | DFND |  | 10000 | 0 | 0 |
| OAKTREE SPECIALTY LENDING | COM | 67401P405 |  | 35000 | 200000 | SH | Put | DFND |  | 200000 | 0 | 0 |
| OLIN CORP | COM PAR $1 | 680665205 |  | 169700 | 236000 | SH | Put | DFND |  | 236000 | 0 | 0 |
| ON SEMICONDUCTOR CORP | NOTE 0.500% 3/0 | 682189AU9 |  | 12250000 | 12500000 | PRN |  | DFND |  | 12500000 | 0 | 0 |
| PACKAGING CORP AMER | COM | 695156109 |  | 318330 | 1500 | SH |  | DFND |  | 1500 | 0 | 0 |
| PAN AMERN SILVER CORP | COM | 697900108 |  | 29375 | 25000 | SH | Call | DFND |  | 25000 | 0 | 0 |
| PENNYMAC CORP | NOTE 8.500% 6/0 | 70932AAH6 |  | 1045589 | 1000000 | PRN |  | DFND |  | 1000000 | 0 | 0 |
| PENNYMAC MTG INVT TR | COM | 70931T103 |  | 2098800 | 180000 | SH |  | DFND |  | 180000 | 0 | 0 |
| POST HLDGS INC | COM | 737446104 |  | 159375 | 75000 | SH | Put | DFND |  | 75000 | 0 | 0 |
| PULTE GROUP INC | COM | 745867101 |  | 164150 | 33500 | SH | Put | DFND |  | 33500 | 0 | 0 |
| QNITY ELECTRONICS INC | COMMON STOCK | 74743L100 |  | 141250 | 50000 | SH | Call | DFND |  | 50000 | 0 | 0 |
| QUANTA SVCS INC | COM | 74762E102 |  | 586500 | 30000 | SH | Call | DFND |  | 30000 | 0 | 0 |
| RANGE RES CORP | COM | 75281A109 |  | 1355400 | 30000 | SH |  | DFND |  | 30000 | 0 | 0 |
| REDFIN CORP | NOTE 0.500% 4/0 | 75737FAE8 |  | 1577555 | 1645000 | PRN |  | DFND |  | 1645000 | 0 | 0 |
| REDWOOD TRUST INC | COM | 758075402 |  | 3087525 | 550361 | SH |  | DFND |  | 550361 | 0 | 0 |
| REDWOOD TRUST INC | NOTE 7.750% 6/1 | 758075AF2 |  | 1827000 | 1800000 | PRN |  | DFND |  | 1800000 | 0 | 0 |
| RITHM CAPITAL CORP | COM NEW | 64828T201 |  | 12632887 | 1332583 | SH |  | DFND |  | 1332583 | 0 | 0 |
| SHIFT4 PMTS INC | CL A | 82452J109 |  | 6340850 | 145000 | SH |  | DFND |  | 145000 | 0 | 0 |
| SHIFT4 PMTS INC | CL A | 82452J109 |  | 488250 | 180000 | SH | Call | DFND |  | 180000 | 0 | 0 |
| SHIFT4 PMTS INC | CL A | 82452J109 |  | 166750 | 145000 | SH | Put | DFND |  | 145000 | 0 | 0 |
| SMURFIT WESTROCK PLC | SHS | G8267P108 |  | 37500 | 50000 | SH | Put | DFND |  | 50000 | 0 | 0 |
| SNOWFLAKE INC | NOTE 10/0 | 833445AB5 |  | 17745000 | 15000000 | PRN |  | DFND |  | 15000000 | 0 | 0 |
| SOLSTICE ADVANCED MATLS INC | COM SHS | 83443Q103 |  | 1142400 | 15000 | SH |  | DFND |  | 15000 | 0 | 0 |
| SPDR SERIES TRUST | STATE STREET SPD | 78464A698 |  | 18600 | 20000 | SH | Put | DFND |  | 20000 | 0 | 0 |
| STATE STR SPDR S 500 ETF T | TR UNIT | 78462F103 |  | 680650 | 630000 | SH | Call | DFND |  | 630000 | 0 | 0 |
| STATE STR SPDR S 500 ETF T | TR UNIT | 78462F103 |  | 5130225 | 755000 | SH | Put | DFND |  | 755000 | 0 | 0 |
| TALEN ENERGY CORP | COM | 87422Q109 |  | 429000 | 60000 | SH | Call | DFND |  | 60000 | 0 | 0 |
| TELEPHONE  DATA SYS INC | COM NEW | 879433829 |  | 210500 | 5000 | SH |  | DFND |  | 5000 | 0 | 0 |
| TPG MTG INVTS TR INC | COM NEW | 001228501 |  | 351567 | 48094 | SH |  | DFND |  | 48094 | 0 | 0 |
| TWO HARBORS INVENTMENT CORPO | COM | 90187B804 |  | 374302 | 32776 | SH |  | DFND |  | 32776 | 0 | 0 |
| UNITED AIRLS HLDGS INC | COM | 910047109 |  | 41000 | 25000 | SH | Put | DFND |  | 25000 | 0 | 0 |
| UNITED STS OIL FD LP | UNITS | 91232N207 |  | 26000 | 200000 | SH | Call | DFND |  | 200000 | 0 | 0 |
| VANGUARD SCOTTSDALE FDS | SHRT TRM CORP BD | 92206C409 |  | 4147486 | 52321 | SH |  | DFND |  | 52321 | 0 | 0 |
| VISTRA CORP | COM | 92840M102 |  | 48750 | 25000 | SH | Call | DFND |  | 25000 | 0 | 0 |
| WALMART INC | COM | 931142103 |  | 902770 | 7264 | SH |  | DFND |  | 7264 | 0 | 0 |
| WALMART INC | COM | 931142103 |  | 13280 | 22700 | SH | Call | DFND |  | 22700 | 0 | 0 |
| WILLIAMS COS INC | COM | 969457100 |  | 3275100 | 45000 | SH |  | DFND |  | 45000 | 0 | 0 |
| WILLIAMS COS INC | COM | 969457100 |  | 155000 | 50000 | SH | Call | DFND |  | 50000 | 0 | 0 |
| WINGSTOP INC | COM | 974155103 |  | 154970 | 1000 | SH |  | DFND |  | 1000 | 0 | 0 |
| WINGSTOP INC | COM | 974155103 |  | 498875 | 32500 | SH | Put | DFND |  | 32500 | 0 | 0 |
| WIX COM LTD | SHS | M98068105 |  | 810630 | 9000 | SH |  | DFND |  | 9000 | 0 | 0 |
| WOLFSPEED INC | COMMON STOCK | 97785W106 |  | 408000 | 25000 | SH |  | DFND |  | 25000 | 0 | 0 |
| WOLFSPEED INC | NOTE 2.500% 6/1 | 977852AP7 |  | 387869 | 271000 | PRN |  | DFND |  | 271000 | 0 | 0 |

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