Core Natural Resources, Inc. (CNR)Oberweis Asset Management Inc added to its stake +91K shares

270K

Shares reported · +91K vs prior quarter

0.83%

Disclosed portfolio weight

$28.3M

Reported value

Holdings as of

Mar 31, 2026

Filed

May 15, 2026

The story around this disclosure

Every dated public record OQRO holds about the company from 60 days before to 120 days after, oldest first. It shows what was going on; none of it is a stated reason for the trade.

1. Mar 17, 2026InsiderOfficer sold ~$98K of CNR shares in the open market
2. Mar 18, 2026Insider · Their largest sale since 2022CEO sold ~$4.12M of CNR shares in the open market
3. Mar 19, 2026Insider · 1 personInsiders: 2 sales (~$1.6M)
4. May 7, 2026Company filing · Form 8-K · Results, Reg FDReported its results, and shared information with investors

What came next

1. Aug 6, 2026Company filing · Form 8-K · Results, Reg FDReported its results, and shared information with investors
2. Aug 18, 2026Company filing · Form 8-K · Executive change, Reg FDChanged a top executive or board member, and shared information with investors“On August 18, 2026, as part of its long-term succession process, the Board of Directors (the “Board”) of Core Natural Resources, Inc. (the “Company”) appointed Nathan Tucker to serve as the Company’s Senior Vice President and Chief Financial Officer, effective immediately, taking over the Chief Financial Officer role from Mitesh Thakkar, who will continue to serve as President of the Company and is assuming an…”

How to read SEC Form 13F-HR

Form 13F is the quarterly report in which investment managers that oversee $100 million or more list the US-listed stocks and some other securities they held on the last day of the quarter.

Full guide: What is an SEC Form 13F?

What else is on file for Core Natural Resources, Inc.

For Core Natural Resources, Inc., OQRO holds 3 fund holdings reports (13F) dated in the last 90 days.

These are records OQRO holds, counted by their date, not a measure of how much trading took place. Routine paperwork such as option exercises and tax withholding is left out. Everything for the company is on its CNR page.

How this filing works

• SEC Form 13F

Other disclosures at Core Natural Resources, Inc.

• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 14, 2026
• SEC Form 13F-HRAug 7, 2026
• SEC Form 13F-HRMay 15, 2026
• SEC Form 13F-HRMay 15, 2026
• SEC Form 13F-HRMay 15, 2026

Everything OQRO holds on this company is on its CNR page.