Comparable stake leader
BlackRock, Inc.
SEC ownership of Quanterix Corp
Top holders, 13D/G large-stake signals, insider positions, and transaction flow tied to CIK 0001503274.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
12 May 2026
- Public ticker
- QTRX on Nasdaq
- Parsed ownership sources
-
13D/G, 13F, and 3/4/5
Source: Parsed SEC ownership filingsUse: Compare filing families carefully
- Largest SEC-reported holder
-
BlackRock, Inc.
Ranking: Comparable ownership first, then disclosed value
- Comparable ownership rows
-
50 of 50
Meaning: Rows with safely comparable ownership %
- Latest 13D/G holder
-
BlackRock, Inc.
Source: Latest parsed Schedule 13D/G stake
- Latest parsed ownership date
-
12 May 2026
Freshness: Most recent filing date in this holder set
- Issuer CIK
- 0001503274
- Issuer location
- Billerica, MA
Ownership snapshot
CIK-linked ownership evidence from parsed SEC filings.
3 signals
Issuer
Names, identifiers, and filing context for this profile.
2 identity fields
Ownership snapshot
Top shareholders of Quanterix Corp (13F + 13D/G + 3/4/5)
Grouped by holder across the latest SEC ownership disclosures. Start with comparable ownership when available, then verify the linked 13F, 13D/G, or 3/4/5 evidence.
Comparable stake leader
BlackRock, Inc.
Disclosed value leader
BlackRock, Inc.
Comparable rows
50/50
Latest evidence
12 May 2026
13D/G
13F
3/4/5
Lead comparable stake: 7.3%
13D/G row: BlackRock, Inc.
Showing 1-8 of 50 holder rows.
Quick read
BlackRock, Inc. leads the comparable SEC ownership view at 7.3%.
50 of 50 rows have a safely comparable ownership percentage. Use this as a filing-backed starting point, then open the detailed table for source links, reporting role, position value, share count, and filing date.
Open SEC evidence
Opens BlackRock, Inc.'s linked filing trail.
Comparable ownership
Top 5
BlackRock, Inc.
7.3%
Portolan Capital Management, LLC
6.2%
Telegraph Hill Partners III, L.P.
5.4%
Kent Lake PR LLC
4.5%
AMERIPRISE FINANCIAL INC
2.1%
Ownership % is shown only when SEC disclosures are safely comparable across share classes.
Detailed SEC evidence table Showing 1-8 of 50 holder rows
| Holder | Evidence | Ownership % | Position | 12M Net Δ | As of |
|---|---|---|---|---|---|
| BlackRock, Inc. |
13D/G
13F
Company
|
7.3%
|
$18,911,004
2,843,760 shares
|
$0 | 30 Jun 2025 |
| Portolan Capital Management, LLC |
13F
13D/G
Company
|
6.2%
from 13D/G
|
$10,369,297
2,945,823 shares
|
— | 31 Mar 2026 |
| Telegraph Hill Partners III, L.P. |
13D/G
|
5.4%
|
$12,523,240
2,504,648 shares
|
$0 | 30 Sep 2025 |
| Kent Lake PR LLC |
13D/G
|
4.5%
|
$13,894,548
2,089,500 shares
|
-$3,694,480 | 11 Jul 2025 |
| AMERIPRISE FINANCIAL INC |
13F
13D/G
Company
|
2.1%
from 13D/G
|
$12,469,155
3,542,374 shares
|
— | 31 Mar 2026 |
| ALLIANCEBERNSTEIN L.P. |
13F
13D/G
Company
|
0.1%
from 13D/G
|
$282,893
44,480 shares
|
— | 31 Mar 2026 |
| Paul M. Meister |
3/4/5
Director
|
0.66%
|
$1,992,414
313,253 shares
|
— | 02 Jan 2026 |
| Alan Bruce Sachs |
3/4/5
Director
|
0.15%
|
$445,885
70,099 shares
|
— | 02 Jan 2026 |
How to read this table
Rows are grouped by holder and ranked first by SEC-reported ownership % when it is safely comparable, then by disclosed holdings value. — indicates unavailable or non-comparable values; "mixed-class rows" means the latest filing spans non-comparable classes.
Forms 3/4/5 flow
Insider trading overview
Net insider flow leans to buying over the last 12 months. Net value: +$29,574.
Buys
$29,574
Insiders: 2
Sells
$0
Insiders: 0
Net
+$29,574
Shares: +7,650
Window
Last 12 months
4 rolling buckets
Buy value
Sell value
Shares: 7,650
Shares: 0
| Window (months) | Buy shares | Sell shares | Buy value | Sell value | Net value |
|---|---|---|---|---|---|
| 0-3 | 3,500 | 0 | $9,695 | $0 | +$9,695 |
| 3-6 | 0 | 0 | $0 | $0 | $0 |
| 6-9 | 0 | 0 | $0 | $0 | $0 |
| 9-12 | 4,150 | 0 | $19,878 | $0 | +$19,878 |
Reporting owners
Insider holders from Forms 3/4/5
Showing 1-20 of 30 reporting-owner rows connected to Quanterix Corp. Open a relationship link for the CIK-to-CIK filing trail.
Rows
30
Largest Forms 3/4/5 holder
E. Kevin Hrusovsky
Net 12M change
+$29,574
Latest report
15 Jul 2026
| Name | Relationship | Holdings Value | Past Year Net Change | Change % | Valuation | Report Date |
|---|---|---|---|---|---|---|
| E. Kevin Hrusovsky | Executive Chairman, Director | $24,494,801 | Mixed | 05 Jul 2022 | ||
| David R. Walt | Director | $11,913,078 | Mixed | 02 Jan 2026 | ||
| Masoud Toloue | President & CEO, Director | $4,033,114 | Mixed | 16 Jan 2026 | ||
| Keith Crandell | Director | $3,531,561 | Mixed | 03 Apr 2023 | ||
| Martin D. Madaus | Director | $3,136,981 | Mixed | 02 Jan 2025 | ||
| Michael A. Doyle | CFO and Treasurer | $2,377,014 | Mixed | 30 Sep 2023 | ||
| Paul M. Meister | Director | $1,992,414 | Mixed | 02 Jan 2026 | ||
| David C. Duffy | SVP R&D and CTO | $1,472,784 | Mixed | 23 Mar 2022 | ||
| John J. Fry | General Counsel & Secretary | $1,013,727 | Mixed | 01 Aug 2022 | ||
| Dawn Mattoon | Sr. VP, Diagnostics | $992,333 | Mixed | 01 Apr 2022 | ||
| Roskey Mark T. | SVP, Strategic Partnerships | $600,766 | Mixed | 01 Apr 2022 | ||
| William P. Donnelly | Director | $564,273 | Mixed | 01 Jul 2026 | ||
| Brian J. Blaser | Director | $512,609 | Mixed | 02 Jan 2024 | ||
| Malcolm Garret Hampton | Director | $445,885 | Mixed | 02 Jan 2026 | ||
| Alan Bruce Sachs | Director | $445,885 | Mixed | 02 Jan 2026 | ||
| Sarah E. Hlavinka | Director | $401,868 | Mixed | 01 Jul 2025 | ||
| Karen Flynn | Director | $363,914 | Mixed | 02 Jan 2026 | ||
| Ivana Magovcevic-Liebisch | Director | $277,357 | Mixed | 02 Jan 2026 | ||
| Jeffrey Thomas Elliott | Director | $272,191 | Mixed | 02 Jan 2026 | ||
| Laurie J. Olson | Director | $233,271 | Filing P/S | 14 May 2024 |
Recent insider transactions for Quanterix Corp
Showing up to 300 recent insider transactions from the last 12 months.
| Insider | Symbol | Class | Transaction | % | SEC-reported value | SEC-reported price | Shares | Shares owned | Date | Ownership |
|---|---|---|---|---|---|---|---|---|---|---|
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -1.32% | -467 | 35,033 | 15 Jul 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 4.48% | 1,558 | 36,317 | 15 Jul 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -72.3% | -1,558 | 598 | 15 Jul 2026 | Direct | ||
| Jason F. Faessler | QTRX | Restricted Stock Unit | Award | 141,820 | 141,820 | 15 Jul 2026 | Direct | |||
| Scott Mendel | QTRX | Common Stock | Options Exercise | 50.5% | 8,073 | 24,056 | 08 Jul 2026 | Direct | ||
| Scott Mendel | QTRX | Restricted Stock Unit | Options Exercise | -33% | -8,073 | 16,391 | 08 Jul 2026 | Direct | ||
| Goldman Myla Lai | QTRX | Common Stock | Options Exercise | 115.9% | 8,073 | 15,041 | 08 Jul 2026 | Direct | ||
| Goldman Myla Lai | QTRX | Restricted Stock Unit | Options Exercise | -33% | -8,073 | 16,391 | 08 Jul 2026 | Direct | ||
| Scott Mendel | QTRX | Common Stock | Award | 25.8% | 3,456 | 16,837 | 01 Jul 2026 | Direct | ||
| William P. Donnelly | QTRX | Common Stock | Award | 3.53% | 5,472 | 160,305 | 01 Jul 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -0.11% | -39 | 34,977 | 30 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 0.37% | 130 | 35,016 | 30 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -31% | -130 | 289 | 30 Jun 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Tax liability | -1.78% | -548 | 30,182 | 15 Jun 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Options Exercise | 6.16% | 1,833 | 31,598 | 15 Jun 2026 | Direct | ||
| Vandana Sriram | QTRX | Restricted Stock Unit | Options Exercise | -33.2% | -1,833 | 3,682 | 15 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -1.36% | -467 | 33,851 | 15 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 4.64% | 1,558 | 35,135 | 15 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -69.6% | -1,558 | 679 | 15 Jun 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -0.12% | -39 | 33,795 | 31 May 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 0.39% | 130 | 33,834 | 31 May 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -23.7% | -130 | 419 | 31 May 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Tax liability | -1.86% | -548 | 28,897 | 15 May 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Options Exercise | 6.44% | 1,833 | 30,313 | 15 May 2026 | Direct | ||
| Vandana Sriram | QTRX | Restricted Stock Unit | Options Exercise | -31.7% | -1,833 | 3,945 | 15 May 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -1.41% | -467 | 32,669 | 15 May 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 4.81% | 1,558 | 33,953 | 15 May 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -67.2% | -1,558 | 760 | 15 May 2026 | Direct | ||
| Benjamin Meadows | QTRX | Common Stock | Purchase | $9,695 | $2.77 | 3,500 | 3,500 | 12 May 2026 | Direct | |
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -0.12% | -39 | 32,613 | 30 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 0.4% | 130 | 32,652 | 30 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -19.2% | -130 | 549 | 30 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -1.46% | -467 | 31,487 | 15 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 4.99% | 1,558 | 32,771 | 15 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -64.9% | -1,558 | 841 | 15 Apr 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Tax liability | -1.95% | -548 | 27,612 | 15 Apr 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Options Exercise | 6.74% | 1,833 | 29,028 | 15 Apr 2026 | Direct | ||
| Vandana Sriram | QTRX | Restricted Stock Unit | Options Exercise | -30.3% | -1,833 | 4,208 | 15 Apr 2026 | Direct | ||
| William P. Donnelly | QTRX | Common Stock | Award | 4.18% | 6,178 | 154,127 | 01 Apr 2026 | Direct | ||
| Scott Mendel | QTRX | Common Stock | Award | 52.4% | 4,310 | 12,527 | 01 Apr 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -0.22% | -69 | 31,340 | 31 Mar 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 0.73% | 229 | 31,470 | 31 Mar 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -100% | -229 | 0 | 31 Mar 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Tax liability | -1.78% | -549 | 30,314 | 15 Mar 2026 | Direct | ||
| Michael Francis Miller | QTRX | Common Stock | Options Exercise | 5.19% | 1,558 | 31,564 | 15 Mar 2026 | Direct | ||
| Michael Francis Miller | QTRX | Restricted Stock Unit | Options Exercise | -62.8% | -1,558 | 922 | 15 Mar 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Tax liability | -2.38% | -645 | 26,410 | 15 Mar 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Options Exercise | 7.06% | 1,833 | 27,799 | 15 Mar 2026 | Direct | ||
| Vandana Sriram | QTRX | Restricted Stock Unit | Options Exercise | -29.1% | -1,833 | 4,471 | 15 Mar 2026 | Direct | ||
| Vandana Sriram | QTRX | Common Stock | Tax liability | -1.03% | -271 | 26,069 | 15 Feb 2026 | Direct |
* marks a reported price that did not pass the local price check.