Who owns NEPH (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-Q1 13F filings. 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 2025-Q4 and 2026-Q1: 1 added or opened and 3 trimmed or exited — on balance reducing.
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 2025-Q4 and 2026-Q1, across 27 tracked filers holding NEPH, 9 increased or opened the position and 20 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 2025-Q4 and 2026-Q1 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.
New buyers 1
- VANGUARD CAPITAL MANAGEMENT LLC$592K
Full exits 1
- VANGUARD GROUP INC$1M
Largest trims
- WEXFORD CAPITAL LP$7M
- Topline Capital Management, LLC$1M
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 trimmed | 3,600,552 | $11M | 59.6% | 2026-Q1 |
| Topline Capital Management, LLC trimmed | 581,967 | $2M | 9.6% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 198,643 | $592K | 3.3% | 2026-Q1 |
| Cornerstone Capital, Inc. new | 128,700 | $384K | 2.1% | 2026-Q1 |
| BARD ASSOCIATES INC trimmed | 121,202 | $361K | 2.0% | 2026-Q1 |
| Mesirow Financial Investment Management, Inc. added | 120,000 | $358K | 2.0% | 2026-Q1 |
| MORGAN STANLEY added | 110,915 | $331K | 1.8% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC trimmed | 99,400 | $296K | 1.6% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC trimmed | 72,925 | $217K | 1.2% | 2026-Q1 |
| HighTower Advisors, LLC | 59,710 | $178K | 1.0% | 2026-Q1 |
| ESSEX INVESTMENT MANAGEMENT CO LLC | 38,984 | $116K | 0.6% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 36,901 | $110K | 0.6% | 2026-Q1 |
| BLAIR WILLIAM & CO/IL | 36,249 | $108K | 0.6% | 2026-Q1 |
| De Lisle Partners LLP | 25,000 | $74K | 0.4% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 20,888 | $62K | 0.3% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 20,745 | $62K | 0.3% | 2026-Q1 |
| NAVELLIER & ASSOCIATES INC trimmed | 19,126 | $57K | 0.3% | 2026-Q1 |
| STATE STREET CORP | 15,698 | $47K | 0.3% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC trimmed | 14,163 | $42K | 0.2% | 2026-Q1 |
| PRELUDE CAPITAL MANAGEMENT, LLC trimmed | 13,680 | $41K | 0.2% | 2026-Q1 |
| ELKHORN PARTNERS LIMITED PARTNERSHIP added | 12,000 | $36K | 0.2% | 2026-Q1 |
| Cannell & Spears LLC | 11,000 | $33K | 0.2% | 2026-Q1 |
| NORTHERN TRUST CORP | 10,828 | $32K | 0.2% | 2026-Q1 |
| ROYAL BANK OF CANADA added | 747 | $2K | 0.0% | 2026-Q1 |
| OSAIC HOLDINGS, INC. trimmed | 175 | $521 | 0.0% | 2026-Q1 |
| HARBOUR INVESTMENTS, INC. | 50 | $149 | 0.0% | 2026-Q1 |
| JONES FINANCIAL COMPANIES LLLP | 31 | $90 | 0.0% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 233,644 | $1M | 6.3% | 2025-Q4 stale |
| Cambridge Investment Research Advisors, Inc. new | 69,149 | $337K | 1.9% | 2025-Q4 stale |
| Quadrature Capital Ltd new | 23,004 | $112K | 0.6% | 2025-Q4 stale |
| MARSHALL WACE, LLP new | 21,983 | $107K | 0.6% | 2025-Q4 stale |
| XTX Topco Ltd added | 21,617 | $105K | 0.6% | 2025-Q4 stale |
| Heron Bay Capital Management new | 13,471 | $66K | 0.4% | 2025-Q4 stale |
| Centiva Capital, LP new | 10,835 | $53K | 0.3% | 2025-Q4 stale |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP trimmed | 10,373 | $49K | 0.3% | 2025-Q3 stale |
| Kestra Advisory Services, LLC new | 6,015 | $29K | 0.2% | 2025-Q4 stale |
| Tower Research Capital LLC (TRC) trimmed | 1,105 | $5K | 0.0% | 2025-Q2 stale |
| SageView Advisory Group, LLC new | 590 | $3K | 0.0% | 2025-Q4 stale |
| BARCLAYS PLC new | 106 | $501 | 0.0% | 2025-Q3 stale |
| BANK OF AMERICA CORP /DE/ trimmed | 73 | $356 | 0.0% | 2025-Q4 stale |
| UBS Group AG trimmed | 66 | $312 | 0.0% | 2025-Q3 stale |
| NewEdge Advisors, LLC trimmed | 27 | $132 | 0.0% | 2025-Q4 stale |
| JPMORGAN CHASE & CO trimmed | 13 | $22 | 0.0% | 2025-Q1 stale |
| CONCOURSE FINANCIAL GROUP SECURITIES, INC. | 0 | — | 0.0% | 2025-Q2 stale |
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.