Boston Partners filed an amended Schedule 13G with the SEC on November 13, 2026, disclosing beneficial ownership of 8,002,638 shares of Cytek Biosciences, Inc. common stock as of September 30, 2026.

Key Highlights

  • Beneficial ownership: Boston Partners reported aggregate beneficial ownership of 8,002,638 shares of Cytek Biosciences common stock.
  • Percent of class: The 8,002,638 shares represent 6.16% of the outstanding common stock, according to the filing.
  • Sole voting power: Boston Partners disclosed sole voting power over 6,503,524 shares.
  • Sole dispositive power: Boston Partners reported sole dispositive power over all 8,002,638 shares, with no shared voting or dispositive power.
  • Client accounts: The filing states the shares are held "for the discretionary account of certain clients."
  • Filer classification: Boston Partners is identified as an investment adviser (type IA), organized in Delaware, with offices at One Beacon Street, 30th Floor, Boston, Massachusetts 02108.

Boston Partners Discloses Amended Ownership Position in Cytek Biosciences

Boston Partners, a Delaware-organized investment adviser, filed Amendment No. 1 to its Schedule 13G disclosing its holdings in Cytek Biosciences, Inc. (NASDAQ:CTKB) as of the event date of September 30, 2026. The filing was submitted November 13, 2026 and signed by Ali Farooqi, Senior Compliance Manager, on behalf of Boston Partners.

According to the filing, Boston Partners beneficially owned 8,002,638 shares of Cytek Biosciences common stock (CUSIP 23285D109), representing 6.16% of the class. Of those shares, 6,503,524 were held with sole voting power, while the remaining shares carried no voting authority by Boston Partners. All 8,002,638 shares were subject to sole dispositive power, with zero shares held under shared dispositive arrangements.

The filing states the shares are held "for the discretionary account of certain clients" and that Boston Partners "may be deemed to be a beneficial owner of such Common Stock" by reason of Rule 13d-3 under the Securities Exchange Act of 1934. The filing further states that, to Boston Partners' knowledge, no single person has the right to receive dividends from or proceeds from the sale of shares representing more than 5% of the outstanding common stock. Cytek Biosciences is headquartered at 47215 Lakeview Boulevard, Fremont, California 94538.

What Was Disclosed

Boston Partners filed an amended Schedule 13G reporting beneficial ownership of 8,002,638 shares, or 6.16%, of Cytek Biosciences common stock as of September 30, 2026, held on behalf of discretionary client accounts, with sole dispositive power over all shares and sole voting power over 6,503,524 shares.