Costco (COST): Sen. Markwayne Mullin disclosed a purchase $15K–$50K

$15,001–$50,000

Reported range · official band, not an exact amount

18 days

Disclosure lag

Traded

Dec 29, 2025

Disclosed

Jan 16, 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. Oct 9, 2025CongressDisclosed purchase of COST — reported range $1,001 - $15,000
2. Oct 17, 2025Congress · 2 peopleMembers of Congress: 1 purchase, 1 sale
3. Nov 5, 2025CongressDisclosed purchase of COST — reported range $1,001 - $15,000
4. Nov 7, 2025FDARecall: Costco Item# 11444 Kirkland Signature Chicken Sandwich with Caesar Salad, refrigerated, packaged in clear plastic clamshell container. The net weight varies as…
5. Nov 7, 2025FDARecall: Costco Item# 19927 Kirkland Signature Caesar Salad, refrigerated, packaged in clear plastic clamshell container. The net weight varies as it is sold by weight.…
6. Nov 7, 2025InsiderOfficer sold ~$2.23M of COST shares in the open market
7. Dec 11, 2025Company filing · Form 8-K · ResultsReported its results
8. Dec 24, 2025CongressDisclosed partial sale of COST — reported range $1,001 - $15,000
9. Dec 29, 2025 · this disclosureCongressDisclosed purchase of COST — reported range $15,001 - $50,000

What came next

1. Dec 29, 2025InsiderOfficer sold ~$1.78M of COST shares in the open market
2. Dec 30, 2025InsiderOfficer sold ~$482K of COST shares in the open market
3. Jan 9, 2026InsiderOfficer sold ~$1.37M of COST shares in the open market
4. Jan 14, 2026InsiderOfficer sold ~$1.41M of COST shares in the open market
5. Jan 16, 2026InsiderDirector sold ~$437K of COST shares in the open market
6. Jan 21, 2026InsiderOfficer sold ~$838K of COST shares in the open market
7. Jan 30, 2026CongressDisclosed purchase of COST — reported range $1,001 - $15,000
8. Jan 31, 2026FDARecall: Kirkland Signature Costco item #1181272 Mini Beignets filled with Caramel 22CT. UPC 000011 812722. Product is packaged in a clear clamshell container. ALLERGEN…
9. Mar 5, 2026Company filing · Form 8-K · ResultsReported its results
10. Mar 9, 2026InsiderOfficer sold ~$732K of COST shares in the open market
11. Mar 26, 20265% stakeThe Vanguard Group reported a passive stake (13G)
12. Apr 1, 2026InsiderOfficer sold ~$695K of COST shares in the open market
13. Apr 6, 2026FDARecall: Kirkland Signature Traditional Madeleines 12 Count/net wt. 18oz., Item #2000012, UPC 000020000127. Plastic clamshell container is packed with 9 pieces of Fille…

How to read Senate eFD periodic transaction report

The STOCK Act is a 2012 US law that requires members of Congress, and some senior staff, to publicly report their stock trades, and those of their spouse and dependent children, within 45 days.

Full guide: What is the STOCK Act?

What else is on file for Costco

For Costco, OQRO holds 6 insider filings (SEC Form 4 or Form 144), 2 Congress trade reports and 106 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 COST page.

Other recent filings by Sen. Markwayne Mullin

• Senate eFD periodic transaction report at UnitedHealth (UNH)Mar 10, 2026
• Senate eFD periodic transaction report at AutoZone (AZO)Mar 10, 2026
• Senate eFD periodic transaction report at Intuit (INTU)Mar 10, 2026
• Senate eFD periodic transaction report at Monolithic Power Systems (MPWR)Mar 2, 2026
• Senate eFD periodic transaction report at McKesson Corporation (MCK)Mar 2, 2026

The full history of Sen. Markwayne Mullin is on the profile page.

How this filing works

• The STOCK Act

Other disclosures at Costco

• House Clerk periodic transaction reportOct 14, 2026
• SEC Form 4Oct 14, 2026
• SEC Form 144Oct 13, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 144Sep 29, 2026

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