Who owns Nephros (NEPH)
Which tracked institutional funds hold NEPH, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See NEPH company fundamentals →
Ownership as of the 2026-Q2 13F filings (latest filed 2026-09-22). 13F is disclosed up to 45 days after quarter-end, so the most recent quarter fills in over the following weeks.
How the tape is positioned
The tracked-fund tape on NEPH is one-sided between 2026-Q1 and 2026-Q2: 1 added or opened and 0 trimmed or exited — on balance accumulating.
A prompt to read the filings, not a verdict. 13F is a quarter-end snapshot disclosed up to 45 days late; a fund adds or exits for mandate, benchmark, and timing reasons that have nothing to do with a view on the stock. This is a starting question, not a signal to trade.
Conviction spread
NEPH’s largest tracked holder by dollar value, WEXFORD CAPITAL LP, sizes it at 1.8% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 1.8pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in NEPH divided by its whole reported 13F book, so it is comparable across funds of different sizes and is unaffected by stock splits. A higher share means a fund has committed more of its book to the name — a starting question about conviction, not a verdict or a signal to trade.
Institutional & insider positioning
Between 2026-Q1 and 2026-Q2, across 31 tracked filers holding NEPH, 13 increased or opened the position and 11 reduced or closed it; over the same quarter, there were no open-market insider Form 4s.
This fuses two public signals for the same quarter — how tracked institutions changed their positions and whether insiders bought or sold in the open market. It describes what was filed; it is a starting question, not a verdict or a signal to trade.
New buyers & exits
Funds opening or closing a position in NEPH between the 2026-Q1 and 2026-Q2 13F filings, and the largest changes among funds holding it in both. New buyers and exits are counted on fund presence (split-invariant); adds and trims are measured on reported value.
Largest adds
- WEXFORD CAPITAL LP$2M
Institutional holders
One row per tracked fund, largest reported value first. “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding. Rows marked stale are from an earlier filing than the security’s latest quarter — that fund is absent from the newest snapshot (position exited, or reported under a different name).
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| WEXFORD CAPITAL LP | 3,600,552 | $13M | 65.0% | 2026-Q2 |
| Topline Capital Management, LLC trimmed | 535,698 | $2M | 9.7% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC | 198,643 | $709K | 3.6% | 2026-Q2 |
| MORGAN STANLEY added | 128,915 | $460K | 2.3% | 2026-Q2 |
| Cornerstone Capital, Inc. | 128,700 | $459K | 2.3% | 2026-Q2 |
| BARD ASSOCIATES INC trimmed | 118,003 | $421K | 2.1% | 2026-Q2 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 77,504 | $277K | 1.4% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 70,263 | $251K | 1.3% | 2026-Q2 |
| Mesirow Financial Investment Management, Inc. trimmed | 60,000 | $214K | 1.1% | 2026-Q2 |
| NAVELLIER & ASSOCIATES INC added | 53,479 | $191K | 1.0% | 2026-Q2 |
| ESSEX INVESTMENT MANAGEMENT CO LLC trimmed | 38,927 | $139K | 0.7% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO | 36,901 | $132K | 0.7% | 2026-Q2 |
| BLAIR WILLIAM & CO/IL | 36,249 | $129K | 0.7% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 29,044 | $104K | 0.5% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP added | 22,164 | $79K | 0.4% | 2026-Q2 |
| De Lisle Partners LLP trimmed | 17,400 | $62K | 0.3% | 2026-Q2 |
| NORTHERN TRUST CORP added | 16,706 | $60K | 0.3% | 2026-Q2 |
| STATE STREET CORP | 15,698 | $56K | 0.3% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 12,836 | $46K | 0.2% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV new | 12,500 | $45K | 0.2% | 2026-Q2 |
| Cannell & Spears LLC | 11,000 | $39K | 0.2% | 2026-Q2 |
| ELKHORN PARTNERS LIMITED PARTNERSHIP trimmed | 11,000 | $39K | 0.2% | 2026-Q2 |
| ROYAL BANK OF CANADA added | 827 | $3K | 0.0% | 2026-Q2 |
| UBS Group AG added | 831 | $3K | 0.0% | 2026-Q2 |
| JONES FINANCIAL COMPANIES LLLP added | 227 | $819 | 0.0% | 2026-Q2 |
| OSAIC HOLDINGS, INC. | 175 | $624 | 0.0% | 2026-Q2 |
| SBI Securities Co., Ltd. new | 150 | $536 | 0.0% | 2026-Q2 |
| NORTHWESTERN MUTUAL WEALTH MANAGEMENT CO new | 133 | $475 | 0.0% | 2026-Q2 |
| HARBOUR INVESTMENTS, INC. | 50 | $179 | 0.0% | 2026-Q2 |
| BARCLAYS PLC trimmed | 27 | $96 | 0.0% | 2026-Q2 |
| FMR LLC new | 6 | $22 | 0.0% | 2026-Q2 |
| HighTower Advisors, LLC | 59,710 | $178K | 0.9% | 2026-Q1 stale (1 quarter behind) |
| PRELUDE CAPITAL MANAGEMENT, LLC trimmed | 13,680 | $41K | 0.2% | 2026-Q1 stale (1 quarter behind) |
| Cambridge Investment Research Advisors, Inc. new | 69,149 | $337K | 1.7% | 2025-Q4 stale (2 quarters behind) |
| Quadrature Capital Ltd new | 23,004 | $112K | 0.6% | 2025-Q4 stale (2 quarters behind) |
| MARSHALL WACE, LLP new | 21,983 | $107K | 0.5% | 2025-Q4 stale (2 quarters behind) |
| XTX Topco Ltd added | 21,617 | $105K | 0.5% | 2025-Q4 stale (2 quarters behind) |
| Heron Bay Capital Management new | 13,471 | $66K | 0.3% | 2025-Q4 stale (2 quarters behind) |
| Centiva Capital, LP new | 10,835 | $53K | 0.3% | 2025-Q4 stale (2 quarters behind) |
| Kestra Advisory Services, LLC new | 6,015 | $29K | 0.1% | 2025-Q4 stale (2 quarters behind) |
| SageView Advisory Group, LLC new | 590 | $3K | 0.0% | 2025-Q4 stale (2 quarters behind) |
| BANK OF AMERICA CORP /DE/ trimmed | 73 | $356 | 0.0% | 2025-Q4 stale (2 quarters behind) |
| NewEdge Advisors, LLC new | 27 | $132 | 0.0% | 2025-Q4 stale (2 quarters behind) |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 10,373 | $49K | 0.2% | 2025-Q3 stale (3 quarters behind) |
| Tower Research Capital LLC (TRC) trimmed | 1,105 | $5K | 0.0% | 2025-Q2 stale (4 quarters behind) |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 0 | — | 0.0% | 2025-Q2 stale (4 quarters behind) |
1 parent filing withheld from the table above, and from the coverage figures, to avoid listing one book twice: VANGUARD GROUP INC (last filed 2025-Q4, 233,644 shares) reconciles to its 2 current affiliates (235,544 shares) — 0.813% apart.
Ownership over time
Tracked institutional holder count and total shares held by filing quarter (independent scales). The curated-era tail and any mid-ingest latest quarter are handled honestly — a partial quarter is not drawn as a collapse.
Reading this table
Funds hold the same stock for different reasons — an index fund “holds” almost everything, an active manager sizes a name to a mandate and a benchmark, and each fund entered at its own price and time. Because 13F is filed up to 45 days after quarter-end, every row is a backward-looking snapshot; a manager may have traded since. Share-class siblings (a company’s A and C shares) are rolled up to one line so a dual-class name is never double-counted. Compare like-for-like. A large holder is not an endorsement, and a fund exiting is not a warning — this is a starting question, not a verdict.
About 13F filings
A Form 13F is a quarterly disclosure that institutional investment managers with over $100 million in US-listed equities must file with the SEC. In plain English: it is a snapshot of the long stock positions a fund held at the end of a quarter. It covers long US-listed equities only — not short positions, options, cash, or private holdings — and the funds shown are the large sample we track, not the complete 13F universe.