Monolithic Power Systems (MPWR)Sen. Markwayne Mullin disclosed a purchase $15K–$50K

$15,001–$50,000

Reported range · official band, not an exact amount

26 days

Disclosure lag

Traded

Feb 4, 2026

Disclosed

Mar 2, 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. Dec 24, 2025Insider · 1 personInsiders: 6 sales (~$952K)
2. Jan 2, 2026Insider · 2 peopleInsiders: 16 sales (~$3.4M)
3. Jan 5, 2026Congress · 1 personMembers of Congress: 2 purchases
4. Jan 8, 20265% stakeBlackRock, Inc. reported a passive stake (13G) of 10.2%
5. Jan 14, 2026Government · Federal Register noticeNotice of Receipt of Complaint; Solicitation of Comments Relating to the Public Interest
6. Feb 2, 2026Insider · 1 personInsiders: 17 sales (~$3.4M)
7. Feb 3, 2026Company filing · Form 8-K · Results, Executive changeChanged a top executive or board member, and reported its results (and 1 more item)“On February 3, 2026, Bernie Blegen informed the Company’s Board of Directors (the “Board”) of his intention to retire from his position as Executive Vice President and Chief Financial Officer.”
8. Feb 4, 2026 · this disclosureCongressDisclosed purchase of MPWR — reported range $15,001 - $50,000

What came next

1. Feb 5, 20265% stakeFMR LLC reported a passive stake (13G) of 8.3%
2. Feb 6, 2026Insider · 5 peopleInsiders: 5 sales (~$170.1M)
3. Feb 9, 2026InsiderDirector sold ~$485K of MPWR shares in the open market
4. Feb 10, 2026Insider · 1 personInsiders: 9 sales (~$38.8M)
5. Feb 11, 2026Insider · 2 peopleInsiders: 11 sales (~$39.5M)
6. Feb 12, 2026Insider · 1 personInsiders: 12 sales (~$38.7M)
7. Feb 17, 2026Government · Federal Register noticeCertain Power Converters, Circuit Board Assemblies, and Computing Systems Containing the Same; Notice of Institution of Investigation
8. Feb 26, 2026Company filing · Form 8-K · RestatementSaid past financial statements can no longer be relied on
9. Mar 27, 20265% stakeThe Vanguard Group reported a passive stake (13G)
10. Apr 29, 20265% stakeVanguard Portfolio Management reported a passive stake (13G) of 5.1%
11. Apr 30, 2026Company filing · Form 8-K · ResultsReported its results
12. Apr 30, 20265% stakeVanguard Capital Management reported a passive stake (13G) of 7.3%

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 Monolithic Power Systems

For Monolithic Power Systems, OQRO holds 33 insider filings (SEC Form 4 or Form 144), 2 Congress trade reports and 23 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 MPWR 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 McKesson Corporation (MCK)Mar 2, 2026
• Senate eFD periodic transaction report at Iron Mountain (IRM)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 Monolithic Power Systems

• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026
• SEC Form 4Sep 30, 2026

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