Who owns MDXG (MDXG)
Which tracked institutional funds hold MDXG, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See MDXG 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 MDXG is one-sided between 2025-Q4 and 2026-Q1: 14 added or opened and 74 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
MDXG’s largest tracked holder by dollar value, Essex Woodlands Management, Inc., sizes it at 44.5% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 44.5pp conviction gap — its largest holder concentrates the name more heavily than the typical one.
Book-share is each fund’s reported value in MDXG 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 238 tracked filers holding MDXG, 137 increased or opened the position and 101 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 MDXG 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 5
- VANGUARD CAPITAL MANAGEMENT LLC$20M
- VANGUARD PORTFOLIO MANAGEMENT LLC$4M
- VANGUARD FIDUCIARY TRUST CO$3M
- GSA CAPITAL PARTNERS LLP$1M
- NORGES BANK$535K
Full exits 5
- VANGUARD GROUP INC$42M
- AMERIPRISE FINANCIAL INC$4M
- Phocas Financial Corp.$3M
- DEERFIELD MANAGEMENT COMPANY, L.P.$1M
- AlphaQuest LLC$769K
Largest adds
- DEUTSCHE BANK AG\$3M
- OP Asset Management Ltd$2M
- LOS ANGELES CAPITAL MANAGEMENT LLC$2M
- UBS Group AG$856K
- AQR CAPITAL MANAGEMENT LLC$825K
- Man Group plc$507K
Largest trims
- Essex Woodlands Management, Inc.$80M
- BlackRock, Inc.$30M
- Trigran Investments, Inc.$13M
- First Light Asset Management, LLC$9M
- GEODE CAPITAL MANAGEMENT, LLC$8M
- DISCIPLINED GROWTH INVESTORS INC /MN$8M
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 |
|---|---|---|---|---|
| Essex Woodlands Management, Inc. | 28,195,249 | $111M | 22.7% | 2026-Q1 |
| BlackRock, Inc. added | 11,911,300 | $47M | 9.6% | 2026-Q1 |
| Trigran Investments, Inc. added | 7,175,109 | $28M | 5.8% | 2026-Q1 |
| VANGUARD CAPITAL MANAGEMENT LLC new | 5,166,006 | $20M | 4.2% | 2026-Q1 |
| STATE STREET CORP added | 5,056,801 | $20M | 4.1% | 2026-Q1 |
| PARADIGM CAPITAL MANAGEMENT INC/NY added | 3,410,300 | $13M | 2.7% | 2026-Q1 |
| Nantahala Capital Management, LLC added | 3,397,299 | $13M | 2.7% | 2026-Q1 |
| RENAISSANCE TECHNOLOGIES LLC added | 3,019,871 | $12M | 2.4% | 2026-Q1 |
| GEODE CAPITAL MANAGEMENT, LLC added | 2,881,159 | $11M | 2.3% | 2026-Q1 |
| First Light Asset Management, LLC trimmed | 2,842,892 | $11M | 2.3% | 2026-Q1 |
| DIMENSIONAL FUND ADVISORS LP added | 2,694,002 | $11M | 2.2% | 2026-Q1 |
| PUNCH & ASSOCIATES INVESTMENT MANAGEMENT, INC. added | 2,019,718 | $8M | 1.6% | 2026-Q1 |
| MARSHALL WACE, LLP added | 1,813,194 | $7M | 1.5% | 2026-Q1 |
| Qube Research & Technologies Ltd added | 1,651,519 | $7M | 1.3% | 2026-Q1 |
| CANNELL CAPITAL LLC added | 1,497,186 | $6M | 1.2% | 2026-Q1 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC added | 1,379,165 | $5M | 1.1% | 2026-Q1 |
| GOLDMAN SACHS GROUP INC added | 1,185,561 | $5M | 1.0% | 2026-Q1 |
| VANGUARD PORTFOLIO MANAGEMENT LLC new | 1,105,718 | $4M | 0.9% | 2026-Q1 |
| Meros Investment Management, LP trimmed | 1,093,028 | $4M | 0.9% | 2026-Q1 |
| DEUTSCHE BANK AG\ added | 1,035,030 | $4M | 0.8% | 2026-Q1 |
| NORTHERN TRUST CORP added | 1,023,106 | $4M | 0.8% | 2026-Q1 |
| AQR CAPITAL MANAGEMENT LLC added | 908,052 | $4M | 0.7% | 2026-Q1 |
| VANGUARD FIDUCIARY TRUST CO new | 822,969 | $3M | 0.7% | 2026-Q1 |
| MORGAN STANLEY added | 812,742 | $3M | 0.7% | 2026-Q1 |
| CITADEL ADVISORS LLC added | 776,441 | $3M | 0.6% | 2026-Q1 |
| ARROWSTREET CAPITAL, LIMITED PARTNERSHIP added | 775,841 | $3M | 0.6% | 2026-Q1 |
| OP Asset Management Ltd added | 609,112 | $3M | 0.6% | 2026-Q1 |
| UBS Group AG added | 673,002 | $3M | 0.5% | 2026-Q1 |
| PRUDENTIAL FINANCIAL INC added | 668,730 | $3M | 0.5% | 2026-Q1 |
| DISCIPLINED GROWTH INVESTORS INC /MN trimmed | 639,066 | $3M | 0.5% | 2026-Q1 |
| BANK OF AMERICA CORP /DE/ added | 572,295 | $2M | 0.5% | 2026-Q1 |
| FIRST TRUST ADVISORS LP added | 553,320 | $2M | 0.4% | 2026-Q1 |
| JANE STREET GROUP, LLC added | 525,472 | $2M | 0.4% | 2026-Q1 |
| LOS ANGELES CAPITAL MANAGEMENT LLC added | 518,847 | $2M | 0.4% | 2026-Q1 |
| Trexquant Investment LP added | 507,401 | $2M | 0.4% | 2026-Q1 |
| ISTHMUS PARTNERS, LLC added | 482,127 | $2M | 0.4% | 2026-Q1 |
| apricus wealth, LLC | 451,945 | $2M | 0.4% | 2026-Q1 |
| LAZARD ASSET MANAGEMENT LLC trimmed | 420,706 | $2M | 0.3% | 2026-Q1 |
| AMERICAN CENTURY COMPANIES INC added | 382,824 | $2M | 0.3% | 2026-Q1 |
| Man Group plc added | 369,527 | $1M | 0.3% | 2026-Q1 |
| Bank of New York Mellon Corp trimmed | 355,701 | $1M | 0.3% | 2026-Q1 |
| HRT FINANCIAL LP added | 340,014 | $1M | 0.3% | 2026-Q1 |
| WELLINGTON MANAGEMENT GROUP LLP trimmed | 336,098 | $1M | 0.3% | 2026-Q1 |
| GSA CAPITAL PARTNERS LLP added | 335,924 | $1M | 0.3% | 2026-Q1 |
| Squarepoint Ops LLC added | 329,216 | $1M | 0.3% | 2026-Q1 |
| D. E. Shaw & Co., Inc. trimmed | 312,696 | $1M | 0.3% | 2026-Q1 |
| STATE OF WISCONSIN INVESTMENT BOARD added | 302,050 | $1M | 0.2% | 2026-Q1 |
| TWO SIGMA INVESTMENTS, LP added | 267,297 | $1M | 0.2% | 2026-Q1 |
| HARBOR CAPITAL ADVISORS, INC. trimmed | 263,369 | $1M | 0.2% | 2026-Q1 |
| VICTORY CAPITAL MANAGEMENT INC added | 259,694 | $1M | 0.2% | 2026-Q1 |
| Fisher Asset Management, LLC added | 246,569 | $974K | 0.2% | 2026-Q1 |
| SG Americas Securities, LLC added | 241,881 | $955K | 0.2% | 2026-Q1 |
| Nuveen, LLC added | 236,888 | $936K | 0.2% | 2026-Q1 |
| Swiss National Bank | 233,400 | $922K | 0.2% | 2026-Q1 |
| ALGERT GLOBAL LLC added | 221,180 | $874K | 0.2% | 2026-Q1 |
| Point72 Asset Management, L.P. trimmed | 214,587 | $848K | 0.2% | 2026-Q1 |
| GLOBEFLEX CAPITAL L P trimmed | 214,350 | $847K | 0.2% | 2026-Q1 |
| UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC added | 210,333 | $831K | 0.2% | 2026-Q1 |
| MILLENNIUM MANAGEMENT LLC trimmed | 200,487 | $792K | 0.2% | 2026-Q1 |
| BARCLAYS PLC trimmed | 187,459 | $740K | 0.2% | 2026-Q1 |
| ALLIANCEBERNSTEIN L.P. trimmed | 108,430 | $734K | 0.1% | 2026-Q1 |
| FRANKLIN RESOURCES INC trimmed | 172,013 | $679K | 0.1% | 2026-Q1 |
| Turtle Creek Wealth Advisors, LLC | 166,700 | $658K | 0.1% | 2026-Q1 |
| State of Wyoming added | 163,115 | $644K | 0.1% | 2026-Q1 |
| HSBC HOLDINGS PLC added | 161,510 | $627K | 0.1% | 2026-Q1 |
| PRINCIPAL FINANCIAL GROUP INC added | 152,833 | $604K | 0.1% | 2026-Q1 |
| RHUMBLINE ADVISERS trimmed | 144,243 | $570K | 0.1% | 2026-Q1 |
| STRS OHIO added | 138,900 | $549K | 0.1% | 2026-Q1 |
| NORGES BANK | 70,400 | $535K | 0.1% | 2026-Q1 |
| Creative Planning added | 135,348 | $535K | 0.1% | 2026-Q1 |
| Pegasus Asset Management, Inc. | 124,000 | $490K | 0.1% | 2026-Q1 |
| Rafferty Asset Management, LLC added | 123,647 | $488K | 0.1% | 2026-Q1 |
| Richmond Brothers, Inc. added | 117,827 | $465K | 0.1% | 2026-Q1 |
| Invesco Ltd. added | 117,763 | $465K | 0.1% | 2026-Q1 |
| STIFEL FINANCIAL CORP trimmed | 117,130 | $463K | 0.1% | 2026-Q1 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 114,524 | $453K | 0.1% | 2026-Q1 |
| SILVERCREST ASSET MANAGEMENT GROUP LLC | 111,160 | $439K | 0.1% | 2026-Q1 |
| CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM trimmed | 107,629 | $425K | 0.1% | 2026-Q1 |
| HEALTHCARE OF ONTARIO PENSION PLAN TRUST FUND | 105,400 | $416K | 0.1% | 2026-Q1 |
| DRW Securities, LLC new | 104,444 | $413K | 0.1% | 2026-Q1 |
| AWH Capital, L.P. trimmed | 100,000 | $395K | 0.1% | 2026-Q1 |
| SkyView Investment Advisors, LLC added | 94,998 | $388K | 0.1% | 2026-Q1 |
| TRUIST FINANCIAL CORP | 96,250 | $380K | 0.1% | 2026-Q1 |
| AVIVA PLC added | 95,491 | $377K | 0.1% | 2026-Q1 |
| AlTi Global, Inc. trimmed | 95,212 | $376K | 0.1% | 2026-Q1 |
| ACADIAN ASSET MANAGEMENT LLC added | 93,697 | $368K | 0.1% | 2026-Q1 |
| Jump Financial, LLC trimmed | 92,884 | $367K | 0.1% | 2026-Q1 |
| VANGUARD GROUP INC trimmed | 6,249,131 | $42M | 8.6% | 2025-Q4 stale |
| AMERIPRISE FINANCIAL INC added | 595,549 | $4M | 0.8% | 2025-Q4 stale |
| Phocas Financial Corp. added | 492,991 | $3M | 0.7% | 2025-Q4 stale |
| HUSSMAN STRATEGIC ADVISORS, INC. new | 252,000 | $2M | 0.4% | 2025-Q3 stale |
| Divisadero Street Capital Management, LP | 223,220 | $2M | 0.3% | 2025-Q3 stale |
| DEERFIELD MANAGEMENT COMPANY, L.P. added | 160,419 | $1M | 0.2% | 2025-Q4 stale |
| AlphaQuest LLC added | 113,618 | $769K | 0.2% | 2025-Q4 stale |
| DLD Asset Management, LP new | 100,000 | $698K | 0.1% | 2025-Q3 stale |
| THOMPSON SIEGEL & WALMSLEY LLC trimmed | 67,615 | $458K | 0.1% | 2025-Q4 stale |
| Corebridge Financial, Inc. trimmed | 58,089 | $441K | 0.1% | 2025-Q1 stale |
| Cubist Systematic Strategies, LLC added | 58,206 | $406K | 0.1% | 2025-Q3 stale |
| Integrated Quantitative Investments LLC added | 58,801 | $398K | 0.1% | 2025-Q4 stale |
| Advantage Alpha Capital Partners LP trimmed | 56,727 | $396K | 0.1% | 2025-Q3 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.