Insider trade

CFO sold ~$253K of MPWR shares in the open market

Traded Nov 3, 2025 · Filed Nov 5, 2025

~$253K
Reported value · 246 sh @ $1,029.45: 75K
Holds after · shares reported: +47.4%
stock since the trade · S&P 500 +13.4%, $1,003.93 → $1,479.89 on Oct 5

Why it stands out

The money chief of Monolithic Power Systems sold $253K of Monolithic Power Systems shares. It was planned long ago, so it says very little.

Written from the filing's own figures. OQRO describes what was reported and never tells you what to buy or sell

View the official recordSEC Form 4 — Statement of Changes in Beneficial Ownership

All the details

Dates, kept separate

Transaction date: Nov 3, 2025
Reporting period: Not applicable
Filed with the SEC: Nov 5, 2025

CFO$100K–$500KPre-arranged plan referenced

Context

Classification

open market sale

Code S — open-market or private sale

Absolute commitment

~$253,245

Shares × reported transaction price

Timing vs results

4 days after results of Oct 30, 2025, 94 days before results of Feb 5, 2026

Results dates are the company's own 8-K (Item 2.02). Many companies only let insiders trade in a window after results

Price at the time

Closed at $1,003.93 on Nov 3, 2025, 121% above its 52-week low and 9% below its high, after a 9% rise over the previous 30 trading days

52-week range $455.19 (Apr 8, 2025) to $1,105.05 (Oct 27, 2025), 84% of the way up, from 250 adjusted closes. 30 trading days earlier: $922.81 on Sep 22, 2025. Describes the past only, not a forecast

Planned / mechanical clue

Footnote references a pre-arranged trading plan (Rule 10b5-1)

Only flagged when a footnote says so; never inferred

Securities lawsuit open at the trade date

A securities lawsuit naming the company as a defendant was filed on Feb 4, 2025 in the U.S. District Court, W.D. Washington. A filing is an allegation, not a finding.

Waterford Township General Employees Retirement System v. Monolithic Power Systems Inc, docket 2:25-cv-00220, via CourtListener (court records). Nature of suit 850, company named as first defendant

After it was reported

After	Stock	S&P 500	Difference
7 days	−4.2%	+0.9%	−5.0%
30 days	−3.7%	+1.2%	−4.9%
90 days	+16.5%	+1.8%	+14.7%
180 days	+57.3%	+6.0%	+51.3%

Past results only. Not a forecast.

Source receipt

Record ID: 0001214659-25-015933
Filed / recorded: Nov 5, 2025, 12:31 AM UTC
Added to OQRO: Oct 2, 2026, 12:28 PM UTC
Parser: form4-xml-v1
Data quality: Verified: identifiers matched exactly
Issuer: MONOLITHIC POWER SYSTEMS INC
Issuer CIK: 1280452
Ticker: MPWR
Reporting person: Theodore Blegen
Relationship: Officer
Officer title: EVP and CFO
Security: Common Stock
Table: Non-derivative (Table I)
Transaction date: Nov 3, 2025
Transaction code: S
Shares / units: 246
Price per share: $1,029.45
Acquired / disposed: Disposed (D)
Shares owned after: 74,950
Ownership form: Direct
Amendment: No

Footnotes from the filing

These transactions were made pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on 2/26/2025.
The price is the weighted average sale price for the transactions reported on this line. The prices for the transactions reported on this line range from $1,029.14 to $1,029.77. The reporting person undertakes to provide, upon request by the staff of the Securities and Exchange Commission, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price.

Around the same time

CFO sold ~$36K of Monolithic Power Systems

Scheduled in advance10mo ago

CFO sold ~$36K of Monolithic Power Systems

Scheduled in advance10mo ago

CFO sold ~$72K of Monolithic Power Systems

Scheduled in advance10mo ago