Who owns Quanterix (QTRX)
Which tracked institutional funds hold QTRX, how they are positioned, and who is buying versus exiting — from SEC Form 13F-HR filings. See QTRX 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
22 tracked funds added or opened QTRX while 15 trimmed or exited it between 2026-Q1 and 2026-Q2 — the tape is split. When large holders disagree on a name, the funds moving first are sometimes ahead of the story.
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
QTRX’s largest tracked holder by dollar value, BlackRock, Inc., sizes it at 0.0% of its own reported 13F book, while the median holder sizes it at 0.0% of theirs — a 0.0pp gap the other way — the median holder sizes QTRX more heavily than its largest holder by dollar value does.
Book-share is each fund’s reported value in QTRX 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 128 tracked filers holding QTRX, 78 increased or opened the position and 64 reduced or closed it; over the same quarter, open-market insider Form 4s were net purchases.
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 QTRX 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.
New buyers 3
- Lionhunter Capital Management, LLC$6M
- JACOBS LEVY EQUITY MANAGEMENT, INC$2M
- Susquehanna Portfolio Strategies, LLC$642K
Full exits 10
- WILLIAM BLAIR INVESTMENT MANAGEMENT, LLC$7M
- Invenomic Capital Management LP$7M
- LEVIN CAPITAL STRATEGIES, L.P.$5M
- Trium Capital LLP$3M
- Empire Financial Management Company, LLC$3M
- ENVESTNET ASSET MANAGEMENT INC$2M
Largest adds
- Blue Water Life Science Advisors, LP$7M
- First Eagle Investment Management, LLC$7M
- AQR CAPITAL MANAGEMENT LLC$6M
- BlackRock, Inc.$4M
- MARSHALL WACE, LLP$2M
- VANGUARD CAPITAL MANAGEMENT LLC$1M
Largest trims
- AMERIPRISE FINANCIAL INC$8M
- MILLENNIUM MANAGEMENT LLC$2M
- Portolan Capital Management, LLC$2M
- Russell Investments Group, Ltd.$2M
- ROYAL BANK OF CANADA$810K
Institutional holders
One row per tracked fund, most shares held first (every row is from one quarter; reported value breaks ties). “% of value” is the fund’s share of this security’s tracked institutional value — not of shares outstanding.
| Fund | Shares | Reported value | % of value | Quarter |
|---|---|---|---|---|
| BlackRock, Inc. added | 3,635,411 | $16M | 12.5% | 2026-Q2 |
| Blue Water Life Science Advisors, LP added | 3,474,202 | $15M | 12.0% | 2026-Q2 |
| First Eagle Investment Management, LLC added | 2,753,165 | $12M | 9.5% | 2026-Q2 |
| Portolan Capital Management, LLC trimmed | 1,899,308 | $8M | 6.6% | 2026-Q2 |
| VANGUARD CAPITAL MANAGEMENT LLC added | 1,800,644 | $8M | 6.2% | 2026-Q2 |
| Lionhunter Capital Management, LLC new | 1,500,427 | $6M | 5.2% | 2026-Q2 |
| AQR CAPITAL MANAGEMENT LLC added | 1,343,005 | $6M | 4.6% | 2026-Q2 |
| GEODE CAPITAL MANAGEMENT, LLC added | 1,131,377 | $5M | 3.9% | 2026-Q2 |
| AMERIPRISE FINANCIAL INC trimmed | 987,424 | $4M | 3.4% | 2026-Q2 |
| MARSHALL WACE, LLP added | 973,872 | $4M | 3.4% | 2026-Q2 |
| STATE STREET CORP added | 932,307 | $4M | 3.2% | 2026-Q2 |
| Tikvah Management LLC trimmed | 571,555 | $2M | 2.0% | 2026-Q2 |
| VANGUARD PORTFOLIO MANAGEMENT LLC trimmed | 489,566 | $2M | 1.7% | 2026-Q2 |
| JACOBS LEVY EQUITY MANAGEMENT, INC new | 487,600 | $2M | 1.7% | 2026-Q2 |
| MORGAN STANLEY trimmed | 447,688 | $2M | 1.5% | 2026-Q2 |
| JANE STREET GROUP, LLC added | 419,050 | $2M | 1.4% | 2026-Q2 |
| TUDOR INVESTMENT CORP ET AL added | 400,402 | $2M | 1.4% | 2026-Q2 |
| DIMENSIONAL FUND ADVISORS LP trimmed | 397,833 | $2M | 1.4% | 2026-Q2 |
| NORTHERN TRUST CORP trimmed | 337,227 | $1M | 1.2% | 2026-Q2 |
| CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed | 310,701 | $1M | 1.1% | 2026-Q2 |
| VANGUARD FIDUCIARY TRUST CO added | 288,311 | $1M | 1.0% | 2026-Q2 |
| UBS Group AG trimmed | 281,978 | $1M | 1.0% | 2026-Q2 |
| Nuveen, LLC added | 232,592 | $1M | 0.8% | 2026-Q2 |
| CITADEL ADVISORS LLC added | 229,736 | $992K | 0.8% | 2026-Q2 |
| XTX Topco Ltd added | 228,035 | $985K | 0.8% | 2026-Q2 |
| Point72 Asset Management, L.P. added | 225,653 | $975K | 0.8% | 2026-Q2 |
| GOLDMAN SACHS GROUP INC trimmed | 212,056 | $916K | 0.7% | 2026-Q2 |
| FMR LLC added | 210,634 | $910K | 0.7% | 2026-Q2 |
| IRONWOOD INVESTMENT MANAGEMENT LLC added | 170,555 | $737K | 0.6% | 2026-Q2 |
| SUSQUEHANNA INTERNATIONAL GROUP, LLP added | 168,620 | $728K | 0.6% | 2026-Q2 |
| Invesco Ltd. added | 160,887 | $695K | 0.6% | 2026-Q2 |
| WELLS FARGO & COMPANY/MN added | 149,158 | $644K | 0.5% | 2026-Q2 |
| Susquehanna Portfolio Strategies, LLC added | 148,618 | $642K | 0.5% | 2026-Q2 |
| BNP PARIBAS FINANCIAL MARKETS added | 136,876 | $591K | 0.5% | 2026-Q2 |
| Bank of New York Mellon Corp added | 131,900 | $570K | 0.5% | 2026-Q2 |
| SCS Capital Management LLC | 120,035 | $519K | 0.4% | 2026-Q2 |
| AMERICAN CENTURY COMPANIES INC trimmed | 100,463 | $434K | 0.3% | 2026-Q2 |
| PRICE T ROWE ASSOCIATES INC /MD/ added | 95,626 | $414K | 0.3% | 2026-Q2 |
| Quadrature Capital Ltd added | 80,200 | $346K | 0.3% | 2026-Q2 |
| Cerity Partners LLC new | 78,083 | $337K | 0.3% | 2026-Q2 |
| BRIDGEWAY CAPITAL MANAGEMENT, LLC | 68,226 | $295K | 0.2% | 2026-Q2 |
| Clearstead Advisors, LLC trimmed | 62,261 | $269K | 0.2% | 2026-Q2 |
| Jain Global LLC added | 57,319 | $248K | 0.2% | 2026-Q2 |
| ALLIANCEBERNSTEIN L.P. added | 56,780 | $200K | 0.2% | 2026-Q2 |
| ALGERT GLOBAL LLC added | 55,217 | $239K | 0.2% | 2026-Q2 |
| RHUMBLINE ADVISERS added | 53,557 | $231K | 0.2% | 2026-Q2 |
| PEDDOCK CAPITAL ADVISORS, LLC | 52,105 | $225K | 0.2% | 2026-Q2 |
| MILLENNIUM MANAGEMENT LLC trimmed | 40,662 | $176K | 0.1% | 2026-Q2 |
| SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC new | 38,961 | $168K | 0.1% | 2026-Q2 |
| CANADA PENSION PLAN INVESTMENT BOARD added | 38,100 | $165K | 0.1% | 2026-Q2 |
| Russell Investments Group, Ltd. trimmed | 37,722 | $163K | 0.1% | 2026-Q2 |
| DEUTSCHE BANK AG\ added | 36,678 | $158K | 0.1% | 2026-Q2 |
| IEQ CAPITAL, LLC new | 35,507 | $153K | 0.1% | 2026-Q2 |
| BANK OF AMERICA CORP /DE/ trimmed | 29,286 | $127K | 0.1% | 2026-Q2 |
| WEALTH ENHANCEMENT ADVISORY SERVICES, LLC new | 26,914 | $104K | 0.1% | 2026-Q2 |
| MERCER GLOBAL ADVISORS INC /ADV added | 25,731 | $111K | 0.1% | 2026-Q2 |
| AXQ CAPITAL, LP added | 25,599 | $111K | 0.1% | 2026-Q2 |
| MetLife Investment Management, LLC added | 24,801 | $107K | 0.1% | 2026-Q2 |
| Aigen Investment Management, LP new | 24,328 | $105K | 0.1% | 2026-Q2 |
| OSAIC HOLDINGS, INC. added | 24,176 | $104K | 0.1% | 2026-Q2 |
| Dynamic Technology Lab Private Ltd trimmed | 20,816 | $90K | 0.1% | 2026-Q2 |
| LPL Financial LLC trimmed | 20,099 | $87K | 0.1% | 2026-Q2 |
| CITIGROUP INC added | 19,713 | $85K | 0.1% | 2026-Q2 |
| MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added | 19,655 | $85K | 0.1% | 2026-Q2 |
| JPMORGAN CHASE & CO added | 19,049 | $86K | 0.1% | 2026-Q2 |
| Creative Planning new | 18,538 | $80K | 0.1% | 2026-Q2 |
| Vanguard Global Advisers, LLC | 18,525 | $80K | 0.1% | 2026-Q2 |
| D. E. Shaw & Co., Inc. trimmed | 17,672 | $76K | 0.1% | 2026-Q2 |
| NISA INVESTMENT ADVISORS, LLC added | 17,356 | $75K | 0.1% | 2026-Q2 |
| BARCLAYS PLC trimmed | 15,805 | $68K | 0.1% | 2026-Q2 |
| HUB Investment Partners, LLC added | 15,734 | $68K | 0.1% | 2026-Q2 |
| Mariner, LLC new | 15,471 | $67K | 0.1% | 2026-Q2 |
| Engineers Gate Manager LP trimmed | 14,807 | $64K | 0.1% | 2026-Q2 |
| Jump Financial, LLC trimmed | 14,700 | $64K | 0.1% | 2026-Q2 |
| CAPTRUST FINANCIAL ADVISORS new | 14,301 | $62K | 0.0% | 2026-Q2 |
| MANUFACTURERS LIFE INSURANCE COMPANY, THE added | 13,788 | $60K | 0.0% | 2026-Q2 |
| Vanguard Personalized Indexing Management, LLC added | 13,239 | $57K | 0.0% | 2026-Q2 |
| PharVision Advisers, LLC trimmed | 13,039 | $56K | 0.0% | 2026-Q2 |
| Schonfeld Strategic Advisors LLC trimmed | 12,663 | $55K | 0.0% | 2026-Q2 |
| Post Resch Tallon Group Inc. | 12,500 | $54K | 0.0% | 2026-Q2 |
| Qube Research & Technologies Ltd trimmed | 11,987 | $52K | 0.0% | 2026-Q2 |
| KESTRA PRIVATE WEALTH SERVICES, LLC added | 11,294 | $49K | 0.0% | 2026-Q2 |
| IMC-Chicago, LLC new | 10,214 | $44K | 0.0% | 2026-Q2 |
| Police & Firemen's Retirement System of New Jersey | 10,062 | $43K | 0.0% | 2026-Q2 |
| Cresset Asset Management, LLC new | 10,000 | $43K | 0.0% | 2026-Q2 |
| Arax Advisory Partners added | 7,558 | $33K | 0.0% | 2026-Q2 |
| SIMPLEX TRADING, LLC added | 7,127 | $31K | 0.0% | 2026-Q2 |
| PNC Financial Services Group, Inc. added | 7,123 | $31K | 0.0% | 2026-Q2 |
| NEW YORK STATE COMMON RETIREMENT FUND | 6,501 | $28K | 0.0% | 2026-Q2 |
| Legal & General Group Plc | 3,993 | $17K | 0.0% | 2026-Q2 |
| Ameritas Investment Partners, Inc. | 3,475 | $15K | 0.0% | 2026-Q2 |
| Tower Research Capital LLC (TRC) trimmed | 3,108 | $13K | 0.0% | 2026-Q2 |
| Sachetta, LLC new | 3,000 | $13K | 0.0% | 2026-Q2 |
| Allworth Financial LP added | 2,143 | $9K | 0.0% | 2026-Q2 |
| GROUP ONE TRADING LLC added | 1,933 | $8K | 0.0% | 2026-Q2 |
| Pinnacle Wealth Planning Services, Inc. | 1,799 | $8K | 0.0% | 2026-Q2 |
| EverSource Wealth Advisors, LLC added | 1,503 | $6K | 0.0% | 2026-Q2 |
| ROYAL BANK OF CANADA trimmed | 1,475 | $7K | 0.0% | 2026-Q2 |
| True Wealth Design, LLC added | 1,068 | $5K | 0.0% | 2026-Q2 |
| NewEdge Advisors, LLC trimmed | 1,000 | $4K | 0.0% | 2026-Q2 |
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.