SCHEDULE 13G/A

NORTHERN TECHNOLOGIES INTERNATIONAL CORP

Common Stock, par value $0.02 per share · CUSIP: 665809109

Event date: 2025-09-30

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

• NEEDHAM INVESTMENT MANAGEMENT L.L.C.

  Shares: 640,000.00 · Class: 6.8%

• NEEDHAM ASSET MANAGEMENT, LLC

  Shares: 640,000.00 · Class: 6.8%

• NEEDHAM AGGRESSIVE GROWTH FUND

  Shares: 640,000.00 · Class: 6.8%

• GEORGE A. NEEDHAM

  Shares: 640,000.00 · Class: 6.8%

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