Quanterix QTRX Institutional Ownership

Updated Oct 11, 2026

Quanterix Corp (NASDAQ:QTRX) was reported as a holding by 131 institutional investors in 13F filings for the quarter ended June 30, 2026.

• Together they owned 62.39% of the outstanding stock in Q2 2026, down from 77.44% a quarter earlier.
• Total holdings of Quanterix shares fell 19.25% from Q1 2026, and the number of holders fell 2.96% from Q2 2025.
• Of the 131 holders, 80 added to their positions, 30 reduced their stakes and 21 left their positions unchanged in Q2 2026.
• Altogether, institutional holders owned 29.43Mn QTRX shares at the end of Q2 2026, down 7.02Mn from the prior quarter and down 4.01Mn from a year earlier.
• As of June 30, 2026, the biggest holder of Quanterix was BlackRock, Inc. with 3.64Mn shares, or 7.71% of shares outstanding.
• The biggest increases in QTRX positions during Q2 2026 came from First Eagle Investment Management, LLC (+1.45Mn shares), Blue Water Life Science Advisors, LP (+1.33Mn shares), AQR Capital Management LLC (+1.26Mn shares), BlackRock, Inc. (+357.82K shares) and Marshall Wace, LLP (+351.49K shares).
• The biggest cuts to QTRX positions during Q2 2026 came from Ameriprise Financial Inc (-2.55Mn shares), Portolan Capital Management, LLC (-1.05Mn shares), Millennium Management LLC (-648.5K shares), Russell Investments Group, Ltd. (-604.26K shares) and Royal Bank of Canada (-230.63K shares).
• Business Quant data shows the 10 biggest positions in Quanterix as of Q2 2026 were held by BlackRock, Inc. (3.64Mn shares), Blue Water Life Science Advisors, LP (3.47Mn shares), First Eagle Investment Management, LLC (2.75Mn shares), Portolan Capital Management, LLC (1.9Mn shares), Vanguard Capital Management LLC (1.8Mn shares), Lionhunter Capital Management, LLC (1.5Mn shares), AQR Capital Management LLC (1.34Mn shares), Geode Capital Management, LLC (1.13Mn shares), Ameriprise Financial Inc (987.42K shares) and Marshall Wace, LLP (973.87K shares).