# EDGAR Filing Document

**Accession Number:** 0001627608
**File Stem:** 0001172661-26-001803
**Filing Date:** 2026-5
**Character Count:** 8363
**Document Hash:** abeb3d0818549f02e1905ada5003c8fb
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001172661-26-001803.hdr.sgml**: 20260513

**ACCESSION NUMBER**: 0001172661-26-001803

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

**PUBLIC DOCUMENT COUNT**: 2

**CONFORMED PERIOD OF REPORT**: 20260331

**FILED AS OF DATE**: 20260513

**DATE AS OF CHANGE**: 20260513

**EFFECTIVENESS DATE**: 20260513

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Monashee Investment Management LLC
- **CENTRAL INDEX KEY:** 0001627608

**ORGANIZATION NAME:**
- **EIN:** 453324374
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1130

**FILING VALUES:**
- **FORM TYPE:** 13F-HR
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 028-16854
- **FILM NUMBER:** 26973295

**BUSINESS ADDRESS:**
- **STREET 1:** 75 PARK PLAZA
- **STREET 2:** 4TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116
- **BUSINESS PHONE:** 6176710048

**MAIL ADDRESS:**
- **STREET 1:** 75 PARK PLAZA
- **STREET 2:** 4TH FLOOR
- **CITY:** BOSTON
- **STATE:** MA
- **ZIP:** 02116

### 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:** Monashee Investment Management LLC<br>**Address:** 75 Park Plaza<br>4th Floor<br>Boston, MA 02116

**Form 13F File Number:** 028-16854

**CRD Number (if applicable):** 000163148

**SEC File Number (if applicable):** 801-79936

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:** Jeff Muller<br>**Title:** COO/CCO<br>**Phone:** 617-671-0048

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

/s/ Jeff Muller  Boston, MA  05-13-2026<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:** 45

**Form 13F Information Table Value Total:** $183824446

      (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 |
| ACLARIS THERAPEUTICS INC | COM | 00461U105 |  | 1875000 | 500000 | SH |  | SOLE |  | 500000 | 0 | 0 |
| ADT INC DEL | COM | 00090Q103 |  | 4599000 | 700000 | SH |  | SOLE |  | 700000 | 0 | 0 |
| AMBIQ MICRO INC | COMMON STOCK | 023193105 |  | 2636440 | 103756 | SH |  | SOLE |  | 103756 | 0 | 0 |
| AST SPACEMOBILE INC | COM CL A | 00217D100 |  | 3729150 | 45000 | SH |  | SOLE |  | 45000 | 0 | 0 |
| BITGO HOLDINGS INC | COM SHS CL A | 091947101 |  | 1234500 | 150000 | SH |  | SOLE |  | 150000 | 0 | 0 |
| BRIDGEBIO PHARMA INC | COM | 10806X102 |  | 4985742 | 67139 | SH |  | SOLE |  | 67139 | 0 | 0 |
| COHERENT CORP | COM | 19247G107 |  | 1191050 | 5000 | SH |  | SOLE |  | 5000 | 0 | 0 |
| COMPASS THERAPEUTICS INC | COM | 20454B104 |  | 1369396 | 258865 | SH |  | SOLE |  | 258865 | 0 | 0 |
| CRISPR THERAPEUTICS AG | NAMEN AKT | H17182108 |  | 2378500 | 50000 | SH |  | SOLE |  | 50000 | 0 | 0 |
| CYTOKINETICS INC | COM NEW | 23282W605 |  | 6591000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| ENERGY VAULT HOLDINGS INC | COM | 29280W109 |  | 582295 | 176453 | SH |  | SOLE |  | 176453 | 0 | 0 |
| ENGENE HOLDINGS INC | COM | 29286M105 |  | 2179200 | 320000 | SH |  | SOLE |  | 320000 | 0 | 0 |
| EVOMMUNE INC | COM SHS | 30054Y107 |  | 4123027 | 179340 | SH |  | SOLE |  | 179340 | 0 | 0 |
| FIGURE TECHNOLOGY SOLUTIO | COM CL A | 349381103 |  | 2597854 | 76520 | SH |  | SOLE |  | 76520 | 0 | 0 |
| FLOWCO HLDGS INC | COM CL A | 342909108 |  | 2060000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| FORGENT POWER SOLUTIONS INC | COM SHS CL A | 34631F102 |  | 10244500 | 350000 | SH |  | SOLE |  | 350000 | 0 | 0 |
| GLOBALFOUNDRIES INC | ORDINARY SHARES | G39387108 |  | 2224000 | 50000 | SH |  | SOLE |  | 50000 | 0 | 0 |
| GOSSAMER BIO INC | NOTE 5.000% 6/0 | 38341PAA0 |  | 845282 | 2167000 | SH |  | SOLE |  | 2167000 | 0 | 0 |
| HALLADOR ENERGY COMPANY | COM | 40609P105 |  | 1465200 | 90000 | SH |  | SOLE |  | 90000 | 0 | 0 |
| HELIX ACQUISITION CORP III | USD CL A ORD SHS | G4444S107 |  | 1393068 | 137113 | SH |  | SOLE |  | 137113 | 0 | 0 |
| INGRAM MICRO HLDG CORP | COM | 457152106 |  | 2331000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| JANUS LIVING INC | CL A-1 | 471024109 |  | 1178500 | 50000 | SH |  | SOLE |  | 50000 | 0 | 0 |
| JOBY AVIATION INC | NOTE 0.750% 2/1 | 47775AAA9 |  | 5858370 | 7000000 | SH |  | SOLE |  | 7000000 | 0 | 0 |
| KKR  CO INC | 6.25 CON SER D | 48251W500 |  | 4022000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| KYMERA THERAPEUTICS INC | COM | 501575104 |  | 2923479 | 35100 | SH |  | SOLE |  | 35100 | 0 | 0 |
| MEDLINE INC | COM CL A | 58507V107 |  | 13350000 | 300000 | SH |  | SOLE |  | 300000 | 0 | 0 |
| MINIMED GROUP INC | COM | 60365F109 |  | 2611000 | 175000 | SH |  | SOLE |  | 175000 | 0 | 0 |
| NAVIGATOR HLDGS LTD | SHS | Y62132108 |  | 1449750 | 75000 | SH |  | SOLE |  | 75000 | 0 | 0 |
| NEKTAR THERAPEUTICS | COM NEW | 640268306 |  | 7195000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| NEXTERA ENERGY INC | UNIT 02/15/2029 | 65339F655 |  | 15215978 | 299970 | SH |  | SOLE |  | 299970 | 0 | 0 |
| NRG ENERGY INC | COM NEW | 629377508 |  | 12421900 | 85000 | SH |  | SOLE |  | 85000 | 0 | 0 |
| ORACLE CORP | 6.5 DEP CUM SR D | 68389X204 |  | 4501000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| PPL CORP | UNIT 02/15/2029 | 69351T866 |  | 5241769 | 101300 | SH |  | SOLE |  | 101300 | 0 | 0 |
| SAB BIOTHERAPEUTICS INC | COM NEW | 78397T202 |  | 1915000 | 500000 | SH |  | SOLE |  | 500000 | 0 | 0 |
| SANDISK CORP | COM | 80004C200 |  | 3176700 | 5000 | SH |  | SOLE |  | 5000 | 0 | 0 |
| SATELLOS BIOSCIENCE INC | COM | 80401L803 |  | 67560 | 12000 | SH |  | SOLE |  | 12000 | 0 | 0 |
| SOLID BIOSCIENCES INC | COM NEW | 83422E204 |  | 10226124 | 1420295 | SH |  | SOLE |  | 1420295 | 0 | 0 |
| SPYGLASS PHARMA INC | COM SHS | 85220G109 |  | 2461450 | 95000 | SH |  | SOLE |  | 95000 | 0 | 0 |
| STRUCTURE THERAPEUTICS INC | SPONSORED ADS | 86366E106 |  | 2410000 | 50000 | SH |  | SOLE |  | 50000 | 0 | 0 |
| TERNS PHARMACEUTICALS INC | COM | 880881107 |  | 15816000 | 300000 | SH |  | SOLE |  | 300000 | 0 | 0 |
| VERADERMICS INC | COMMON STOCK | 922967104 |  | 3157500 | 50000 | SH |  | SOLE |  | 50000 | 0 | 0 |
| VIR BIOTECHNOLOGY INC | COM | 92764N102 |  | 896000 | 100000 | SH |  | SOLE |  | 100000 | 0 | 0 |
| WHITEFIBER INC | SHS | G96115103 |  | 952800 | 80000 | SH |  | SOLE |  | 80000 | 0 | 0 |
| ZENAS BIOPHARMA INC | COM | 98937L105 |  | 2932500 | 150000 | SH |  | SOLE |  | 150000 | 0 | 0 |
| ZENAS BIOPHARMA INC | NOTE 2.500% 4/0 | 98937LAA3 |  | 3208862 | 3152000 | SH |  | SOLE |  | 3152000 | 0 | 0 |

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