Ameriprise Financial, Inc. Reports 7.5% Stake in Quanterix Corp via Schedule 13G/A

Ameriprise Financial, Inc. (AFI) filed a Schedule 13G/A on May 15, 2026, disclosing a significant increase in its holdings of Quanterix Corp (QTRX). As of the event date on March 31, 2026, the reporting person beneficially owns 3,542,374 shares of common stock, representing 7.5% of the company. This marks a substantial rise from a previously reported 0.0% position, indicating a new major stake. The filing, which is the fifth amendment to the original schedule, specifies that AFI holds shared voting and dispositive power over all 3,542,374 shares. The shares were acquired in the ordinary course of business and are not held for the purpose of changing or influencing the control of the issuer. While AFI is the reporting person as a parent holding company, it disclaims beneficial ownership of the reported shares. The filing was signed by Michael G. Clarke, Senior Vice President at Ameriprise Financial, Inc. headquartered in Minneapolis, MN.