Reported book
$1.7B
13F equity value
Institutional filer · SEC 13F · Q4 2025
MARINER INVESTMENT GROUP LLC
The reported 13F portfolio of MARINER INVESTMENT GROUP LLC (CIK 1096978) - top holdings, how concentrated the book is, and what changed last quarter.
- $1.7B
- Reported book
- 101
- Positions
- #44
- of 360 filers
The verdict
MARINER INVESTMENT GROUP LLC runs a large institutional book - $1.7B across 101 reported positions as of Q4 2025, a moderately concentrated portfolio.
- $1.7B
- reported 13F value
- 101
- disclosed positions
- 9.7%
- in MICROSOFT CORP
- #44
- of 360 filers
Reflects long US-equity positions reported to the SEC as of Q4 2025; 13F excludes shorts, cash, non-US and most derivatives, so this is not total AUM.
How to read this page
This page reconstructs an institutional manager's reported equity portfolio from its quarterly SEC Form 13F-HR filings. Any investment manager with at least $100 million in qualifying US-listed equity assets must file a 13F with the Securities and Exchange Commission within 45 days of each quarter-end, disclosing the long positions it held on the last day of that quarter. The "reported book" shown here is the total market value of those disclosed positions, it is not the firm's total assets under management, because 13F covers only long US-listed equities and a defined set of options and convertibles. Short positions, cash, private holdings, sovereign debt, most fixed income, non-US equities, and derivatives are all excluded by rule, so a manager's true economic exposure can differ materially from what appears here. "Positions" counts the distinct securities disclosed; "% of book" shows how much weight each holding carries. Treat these figures as a quarter-lagged snapshot for understanding how a manager is positioned - not as live holdings or investment advice. Each line traces back to a specific filing on SEC EDGAR. This page is provided for informational purposes only and is not financial advice, consult a licensed financial advisor before making investment decisions.
Positions
101
Disclosed securities
Top-5 weight
36%
Of reported book
Largest position
9.7%
MICROSOFT CORP
Core + tail
Top-5 position weight
Top-5 position weight 36.0%
The five largest positions make up about 36% of MARINER INVESTMENT GROUP LLC's reported book as of Q4 2025.
Top Reported Holdings
| # | Security | Value | % of book |
|---|---|---|---|
| 1 | MICROSOFT CORP | $166.4M | 9.7% |
| 2 | LAM RESEARCH CORP | $126.0M | 7.4% |
| 3 | ALPHABET INC | $109.8M | 6.4% |
| 4 | COSTCO WHSL CORP NEW | $107.8M | 6.3% |
| 5 | ISHARES BITCOIN TRUST ETF | $106.6M | 6.2% |
| 6 | CISCO SYS INC | $105.7M | 6.2% |
| 7 | ASML HOLDING N V | $99.5M | 5.8% |
| 8 | TEXAS INSTRS INC | $97.0M | 5.7% |
| 9 | NVIDIA CORPORATION | $92.7M | 5.4% |
| 10 | LINDE PLC | $85.3M | 5.0% |
| 11 | INTEL CORP | $81.2M | 4.7% |
| 12 | HONEYWELL INTL INC | $76.5M | 4.5% |
| 13 | APPLE INC | $67.4M | 3.9% |
| 14 | MASTERCARD INCORPORATED | $57.1M | 3.3% |
| 15 | CINTAS CORP | $50.6M | 3.0% |
| 16 | MCDONALDS CORP | $49.8M | 2.9% |
| 17 | LOWES COS INC | $24.4M | 1.4% |
| 18 | ALIBABA GROUP HLDG LTD | $23.3M | 1.4% |
| 19 | FORD MTR CO | $20.8M | 1.2% |
| 20 | ISHARES TR | $20.2M | 1.2% |
| 21 | FLUOR CORP | $17.2M | 1.0% |
| 22 | NEXTERA ENERGY CAP HLDGS INC | $12.4M | 0.7% |
| 23 | ON SEMICONDUCTOR CORP | $9.5M | 0.6% |
| 24 | RITHM CAPITAL CORP | $9.5M | 0.6% |
| 25 | SHIFT4 PMTS INC | $7.9M | 0.5% |
Latest Quarter Trades · Q4 2025
New positions (101)
MICROSOFT CORP $166.4M
LAM RESEARCH CORP $126.0M
ALPHABET INC $109.8M
COSTCO WHSL CORP NEW $107.8M
ISHARES BITCOIN ETF $106.6M
CISCO SYS INC $105.7M
Reading MARINER INVESTMENT GROUP LLC's book
A concentrated core with a diversified tail.
- Open any holding to see who else owns it and how concentrated that stock is. Browse stocks
- Compare this manager against the largest 13F filers by book size. Top funds by AUM
- Remember 13F shows long positions only, not total AUM, shorts or non-US holdings. 13F limitations
Informational only, not investment advice. 13F is a 45-day-lagged quarterly snapshot; positions may have changed since the filing date.
Frequently Asked Questions
How big is MARINER INVESTMENT GROUP LLC's 13F portfolio?▼
MARINER INVESTMENT GROUP LLC reports $1.7B of long US-equity positions across 101 securities as of Q4 2025. This reflects 13F-disclosed holdings only, it is not the firm's total assets under management.
What is MARINER INVESTMENT GROUP LLC's largest position?▼
MARINER INVESTMENT GROUP LLC's largest reported position is MICROSOFT CORP at $166.4M, about 9.7% of its reported book as of Q4 2025.
What did MARINER INVESTMENT GROUP LLC trade last quarter?▼
In its Q4 2025 filing, MARINER INVESTMENT GROUP LLC opened 101 new positions. Each change is drawn from a line in the firm's 13F-HR filing and can be verified on SEC EDGAR.
Where does MARINER INVESTMENT GROUP LLC's holdings data come from?▼
Every figure renders live from MARINER INVESTMENT GROUP LLC's SEC Form 13F-HR filings in EDGAR, a mandatory quarterly disclosure of long US-listed equity positions, filed within 45 days of quarter-end.
Source: U.S. Securities and Exchange Commission (SEC) - EDGAR Form 13F-HR institutional holdings filings · Q4 2025 13F-HR discloses long US-listed equity positions of managers with $100M+ qualifying assets, filed within 45 days of period end. Reported value is not total AUM.