Clean Harbors (CLH)Westfield Capital Management Co LP added to its stake +7,256 shares

268K

Shares reported · +7,256 vs prior quarter

0.26%

Disclosed portfolio weight

$80.2M

Reported value

Holdings as of

Jun 30, 2026

Filed

Aug 12, 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. Feb 10, 2026Federal contract · $547K obligatedDepartment of Agriculture awarded CLEAN HARBORS INC: $547K obligated to date
2. Feb 20, 2026InsiderCFO sold ~$784K of CLH shares in the open market
3. Feb 23, 2026InsiderCEO sold ~$700K of CLH shares in the open market
4. Mar 18, 2026InsiderCEO sold ~$293K of CLH shares in the open market
5. Apr 22, 2026Federal contract · $1.1M obligatedDepartment of Defense awarded CLEAN HARBORS INC: $1.05M obligated to date
6. Jun 14, 2026Federal contract · $455K obligatedDepartment of the Treasury awarded CLEAN HARBORS INC: $455K obligated to date
7. Jun 26, 2026Federal contract · $669K obligatedDepartment of Defense awarded CLEAN HARBORS INC: $669K obligated to date
8. Jul 24, 2026CongressDisclosed partial sale of CLH — reported range $1,001 - $15,000
9. Jul 27, 2026CongressDisclosed partial sale of CLH — reported range $1,001 - $15,000
10. Jul 28, 2026CongressDisclosed partial sale of CLH — reported range $1,001 - $15,000
11. Jul 29, 2026Company filing · Form 8-K · ResultsReported its results
12. Aug 3, 2026InsiderDirector sold ~$248K of CLH shares in the open market

What came next

1. Aug 14, 2026InsiderCEO sold ~$803K of CLH shares in the open market
2. Aug 25, 2026CongressDisclosed sale of CLH — reported range $50,001 - $100,000
3. Oct 1, 2026Company filing · Form 8-K · Material agreement, New debtSigned an important agreement, and took on new debt or obligations (and 1 more item)

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 Clean Harbors

For Clean Harbors, OQRO holds 5 insider filings (SEC Form 4 or Form 144), 4 Congress trade reports, 14 fund holdings reports (13F) and 2 federal contract awards 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 CLH page.

How this filing works

• SEC Form 13F

Other disclosures at Clean Harbors

• House Clerk periodic transaction reportSep 9, 2026
• USAspending.gov award recordAug 28, 2026
• USAspending.gov award recordAug 27, 2026
• SEC Form 4Aug 18, 2026
• SEC Form 4Aug 14, 2026
• SEC Form 4Aug 14, 2026

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