Insider trade

Officer sold ~$172K of MPWR shares in the open market

Traded Mar 30, 2026 · Filed Apr 1, 2026

~$172K
Reported value · 166 sh @ $1,035.60: 175K
Holds after · shares reported: +35.8%
stock since the trade · S&P 500 +20.9%, $1,002.34 → $1,360.97 on Oct 1

Why it stands out

Monolithic Power Systems's & General Counsel sold $172K 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: Mar 30, 2026
Reporting period: Not applicable
Filed with the SEC: Apr 1, 2026

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

Context

Classification

open market sale

Code S — open-market or private sale

Absolute commitment

~$171,910

Shares × reported transaction price

Timing vs results

53 days after results of Feb 5, 2026, 31 days before results of Apr 30, 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 $1,002.34 on Mar 30, 2026, 120% above its 52-week low and 19% below its high, after a 14% drop over the previous 30 trading days

52-week range $455.19 (Apr 8, 2025) to $1,231.95 (Feb 25, 2026), 70% of the way up, from 251 adjusted closes. 30 trading days earlier: $1,171.47 on Feb 13, 2026. 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	+19.3%	+3.7%	+15.6%
30 days	+40.7%	+9.5%	+31.2%
90 days	+19.1%	+13.7%	+5.3%
180 days	+21.2%	+16.5%	+4.7%

Past results only. Not a forecast.

Source receipt

Record ID: 0001214659-26-004185
Filed / recorded: Apr 1, 2026, 10:41 PM 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: Saria Tseng
Relationship: Officer
Officer title: EVP & General Counsel
Security: Common Stock
Table: Non-derivative (Table I)
Transaction date: Mar 30, 2026
Transaction code: S
Shares / units: 166
Price per share: $1,035.60
Acquired / disposed: Disposed (D)
Shares owned after: 175,062
Ownership form: Direct
Amendment: No

Footnotes from the filing

These transactions were made pursuant to a Rule 10b5-1 trading plan adopted on 11/28/2025.
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 $1,033.98 to $1,037.25. 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

Officer sold ~$709K of Monolithic Power Systems

Scheduled in advance6mo ago

Officer sold ~$457K of Monolithic Power Systems

Scheduled in advance6mo ago

Officer sold ~$307K of Monolithic Power Systems

Scheduled in advance6mo ago