SCHEDULE 13G/A

Quanterix Corp

Common Stock · CUSIP: 74766Q101

Event date: 2025-03-31

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Ameriprise Financial, Inc.

  Shares: 3,715,238 · Class: 9.6%

• TAM UK International Holdings Limited

  Shares: 2,999,012 · Class: 7.7%

• Threadneedle Holdings Limited

  Shares: 2,999,012 · Class: 7.7%

• TAM UK Holdings Limited

  Shares: 2,999,012 · Class: 7.7%

• Threadneedle Asset Management Holdings Limited

  Shares: 2,999,012 · Class: 7.7%

• TC Financing Ltd

  Shares: 2,999,012 · Class: 7.7%

• Threadneedle Asset Management Limited

  Shares: 2,999,012 · Class: 7.7%

• Threadneedle Investment Services Limited

  Shares: 2,999,012 · Class: 7.7%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.