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Institutional Ownership · SEC Form 13F

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.

128
Institutional holders
29M
Shares held (tracked funds)
62.0%
Of shares outstanding

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.

FundSharesReported value% of valueQuarter
BlackRock, Inc. added3,635,411$16M12.5%2026-Q2
Blue Water Life Science Advisors, LP added3,474,202$15M12.0%2026-Q2
First Eagle Investment Management, LLC added2,753,165$12M9.5%2026-Q2
Portolan Capital Management, LLC trimmed1,899,308$8M6.6%2026-Q2
VANGUARD CAPITAL MANAGEMENT LLC added1,800,644$8M6.2%2026-Q2
Lionhunter Capital Management, LLC new1,500,427$6M5.2%2026-Q2
AQR CAPITAL MANAGEMENT LLC added1,343,005$6M4.6%2026-Q2
GEODE CAPITAL MANAGEMENT, LLC added1,131,377$5M3.9%2026-Q2
AMERIPRISE FINANCIAL INC trimmed987,424$4M3.4%2026-Q2
MARSHALL WACE, LLP added973,872$4M3.4%2026-Q2
STATE STREET CORP added932,307$4M3.2%2026-Q2
Tikvah Management LLC trimmed571,555$2M2.0%2026-Q2
VANGUARD PORTFOLIO MANAGEMENT LLC trimmed489,566$2M1.7%2026-Q2
JACOBS LEVY EQUITY MANAGEMENT, INC new487,600$2M1.7%2026-Q2
MORGAN STANLEY trimmed447,688$2M1.5%2026-Q2
JANE STREET GROUP, LLC added419,050$2M1.4%2026-Q2
TUDOR INVESTMENT CORP ET AL added400,402$2M1.4%2026-Q2
DIMENSIONAL FUND ADVISORS LP trimmed397,833$2M1.4%2026-Q2
NORTHERN TRUST CORP trimmed337,227$1M1.2%2026-Q2
CHARLES SCHWAB INVESTMENT MANAGEMENT INC trimmed310,701$1M1.1%2026-Q2
VANGUARD FIDUCIARY TRUST CO added288,311$1M1.0%2026-Q2
UBS Group AG trimmed281,978$1M1.0%2026-Q2
Nuveen, LLC added232,592$1M0.8%2026-Q2
CITADEL ADVISORS LLC added229,736$992K0.8%2026-Q2
XTX Topco Ltd added228,035$985K0.8%2026-Q2
Point72 Asset Management, L.P. added225,653$975K0.8%2026-Q2
GOLDMAN SACHS GROUP INC trimmed212,056$916K0.7%2026-Q2
FMR LLC added210,634$910K0.7%2026-Q2
IRONWOOD INVESTMENT MANAGEMENT LLC added170,555$737K0.6%2026-Q2
SUSQUEHANNA INTERNATIONAL GROUP, LLP added168,620$728K0.6%2026-Q2
Invesco Ltd. added160,887$695K0.6%2026-Q2
WELLS FARGO & COMPANY/MN added149,158$644K0.5%2026-Q2
Susquehanna Portfolio Strategies, LLC added148,618$642K0.5%2026-Q2
BNP PARIBAS FINANCIAL MARKETS added136,876$591K0.5%2026-Q2
Bank of New York Mellon Corp added131,900$570K0.5%2026-Q2
SCS Capital Management LLC120,035$519K0.4%2026-Q2
AMERICAN CENTURY COMPANIES INC trimmed100,463$434K0.3%2026-Q2
PRICE T ROWE ASSOCIATES INC /MD/ added95,626$414K0.3%2026-Q2
Quadrature Capital Ltd added80,200$346K0.3%2026-Q2
Cerity Partners LLC new78,083$337K0.3%2026-Q2
BRIDGEWAY CAPITAL MANAGEMENT, LLC68,226$295K0.2%2026-Q2
Clearstead Advisors, LLC trimmed62,261$269K0.2%2026-Q2
Jain Global LLC added57,319$248K0.2%2026-Q2
ALLIANCEBERNSTEIN L.P. added56,780$200K0.2%2026-Q2
ALGERT GLOBAL LLC added55,217$239K0.2%2026-Q2
RHUMBLINE ADVISERS added53,557$231K0.2%2026-Q2
PEDDOCK CAPITAL ADVISORS, LLC52,105$225K0.2%2026-Q2
MILLENNIUM MANAGEMENT LLC trimmed40,662$176K0.1%2026-Q2
SUSQUEHANNA FUNDAMENTAL INVESTMENTS, LLC new38,961$168K0.1%2026-Q2
CANADA PENSION PLAN INVESTMENT BOARD added38,100$165K0.1%2026-Q2
Russell Investments Group, Ltd. trimmed37,722$163K0.1%2026-Q2
DEUTSCHE BANK AG\ added36,678$158K0.1%2026-Q2
IEQ CAPITAL, LLC new35,507$153K0.1%2026-Q2
BANK OF AMERICA CORP /DE/ trimmed29,286$127K0.1%2026-Q2
WEALTH ENHANCEMENT ADVISORY SERVICES, LLC new26,914$104K0.1%2026-Q2
MERCER GLOBAL ADVISORS INC /ADV added25,731$111K0.1%2026-Q2
AXQ CAPITAL, LP added25,599$111K0.1%2026-Q2
MetLife Investment Management, LLC added24,801$107K0.1%2026-Q2
Aigen Investment Management, LP new24,328$105K0.1%2026-Q2
OSAIC HOLDINGS, INC. added24,176$104K0.1%2026-Q2
Dynamic Technology Lab Private Ltd trimmed20,816$90K0.1%2026-Q2
LPL Financial LLC trimmed20,099$87K0.1%2026-Q2
CITIGROUP INC added19,713$85K0.1%2026-Q2
MIRAE ASSET GLOBAL ETFS HOLDINGS Ltd. added19,655$85K0.1%2026-Q2
JPMORGAN CHASE & CO added19,049$86K0.1%2026-Q2
Creative Planning new18,538$80K0.1%2026-Q2
Vanguard Global Advisers, LLC18,525$80K0.1%2026-Q2
D. E. Shaw & Co., Inc. trimmed17,672$76K0.1%2026-Q2
NISA INVESTMENT ADVISORS, LLC added17,356$75K0.1%2026-Q2
BARCLAYS PLC trimmed15,805$68K0.1%2026-Q2
HUB Investment Partners, LLC added15,734$68K0.1%2026-Q2
Mariner, LLC new15,471$67K0.1%2026-Q2
Engineers Gate Manager LP trimmed14,807$64K0.1%2026-Q2
Jump Financial, LLC trimmed14,700$64K0.1%2026-Q2
CAPTRUST FINANCIAL ADVISORS new14,301$62K0.0%2026-Q2
MANUFACTURERS LIFE INSURANCE COMPANY, THE added13,788$60K0.0%2026-Q2
Vanguard Personalized Indexing Management, LLC added13,239$57K0.0%2026-Q2
PharVision Advisers, LLC trimmed13,039$56K0.0%2026-Q2
Schonfeld Strategic Advisors LLC trimmed12,663$55K0.0%2026-Q2
Post Resch Tallon Group Inc.12,500$54K0.0%2026-Q2
Qube Research & Technologies Ltd trimmed11,987$52K0.0%2026-Q2
KESTRA PRIVATE WEALTH SERVICES, LLC added11,294$49K0.0%2026-Q2
IMC-Chicago, LLC new10,214$44K0.0%2026-Q2
Police & Firemen's Retirement System of New Jersey10,062$43K0.0%2026-Q2
Cresset Asset Management, LLC new10,000$43K0.0%2026-Q2
Arax Advisory Partners added7,558$33K0.0%2026-Q2
SIMPLEX TRADING, LLC added7,127$31K0.0%2026-Q2
PNC Financial Services Group, Inc. added7,123$31K0.0%2026-Q2
NEW YORK STATE COMMON RETIREMENT FUND6,501$28K0.0%2026-Q2
Legal & General Group Plc3,993$17K0.0%2026-Q2
Ameritas Investment Partners, Inc.3,475$15K0.0%2026-Q2
Tower Research Capital LLC (TRC) trimmed3,108$13K0.0%2026-Q2
Sachetta, LLC new3,000$13K0.0%2026-Q2
Allworth Financial LP added2,143$9K0.0%2026-Q2
GROUP ONE TRADING LLC added1,933$8K0.0%2026-Q2
Pinnacle Wealth Planning Services, Inc.1,799$8K0.0%2026-Q2
EverSource Wealth Advisors, LLC added1,503$6K0.0%2026-Q2
ROYAL BANK OF CANADA trimmed1,475$7K0.0%2026-Q2
True Wealth Design, LLC added1,068$5K0.0%2026-Q2
NewEdge Advisors, LLC trimmed1,000$4K0.0%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.

HoldersTotal shares

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.

Learn how to read institutional ownership