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MPWR Insider Trading & Form 4 Activity

MONOLITHIC POWER SYSTEMS, INC.
Last filing: Sep 30, 2026·24 days ago
BEARISH · LAST 90 DAYS
0%
buyers
$0
0 buys
$326K
5 sells
-$326K
net selling
2
insiders
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Net flow — last 12 months

Monthly net of insider buys minus sells. Green months indicate net buying; red months indicate net selling.

Most active insiders

Ranked by total transaction value over the last 90 days.

INSIDERBOUGHTSOLDNET
Hsing Michael
CEO
—
$40.3M
-$40.3M
Dean Robert W II
Interim CFO
—
$191K
-$191K
Chang Kuo Wei Herbert
Director
—
$135K
-$135K
Sciammas Maurice
EVP, WW Sales & Marketing
—
$40K
-$40K
Tseng Saria
EVP & General Counsel
—
—
$0

Recent transactions

Every Form 4 transaction for MPWR, newest first.

SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
596 sh @ $1323.31
$789K
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
130 sh @ $1356.94
$176K
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
10,967 sh @ $1351.43
$14.8M
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
6,343 sh @ $1347.15
$8.5M
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
5,783 sh @ $1343.76
$7.8M
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
2,949 sh @ $1338.66
$3.9M
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
1,111 sh @ $1333.34
$1.5M
SELL10b5-1
Hsing Michael · CEO
Tx Sep 28·Filed Sep 30·EDGAR ↗
2,121 sh @ $1328.54
$2.8M
GIFT
Tseng Saria · EVP & General Counsel
Tx Aug 31·Filed Sep 2·EDGAR ↗
2,000 sh
—
OTHER
Dean Robert W II · Interim CFO
Tx Aug 24·Filed Aug 26·EDGAR ↗
5 sh
—
SELL
Dean Robert W II · Interim CFO
Tx Aug 24·Filed Aug 26·EDGAR ↗
32 sh @ $1297.72
$42K
SELL
Chang Kuo Wei Herbert · Director
Tx Aug 24·Filed Aug 25·EDGAR ↗
50 sh @ $1281.57
$64K
SELL
Dean Robert W II · Interim CFO
Tx Aug 17·Filed Aug 19·EDGAR ↗
6 sh @ $1413.64
$8K
SELL
Chang Kuo Wei Herbert · Director
Tx Aug 11·Filed Aug 13·EDGAR ↗
50 sh @ $1420.00
$71K
SELL
Dean Robert W II · Interim CFO
Tx Aug 5·Filed Aug 6·EDGAR ↗
105 sh @ $1344.27
$141K
GIFT
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Aug 4·Filed Aug 6·EDGAR ↗
25,000 sh
—
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Aug 3·Filed Aug 5·EDGAR ↗
30 sh @ $1343.94
$40K
AWARD
Dean Robert W II · Interim CFO
Tx Jul 25·Filed Jul 28·EDGAR ↗
1,359 sh
—
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
117 sh @ $1400.45
$164K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
213 sh @ $1396.16
$297K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
410 sh @ $1384.11
$567K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
418 sh @ $1378.73
$576K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
472 sh @ $1375.47
$649K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
240 sh @ $1369.18
$329K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
50 sh @ $1359.36
$68K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
5,640 sh @ $1352.95
$7.6M
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
110 sh @ $1405.71
$155K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
1,864 sh @ $1344.16
$2.5M
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
1,460 sh @ $1339.59
$2.0M
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
776 sh @ $1334.59
$1.0M
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
464 sh @ $1329.30
$617K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
409 sh @ $1323.93
$541K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
274 sh @ $1318.42
$361K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
527 sh @ $1314.03
$692K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 15·Filed Jul 17·EDGAR ↗
1,506 sh @ $1348.91
$2.0M
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jul 1·Filed Jul 6·EDGAR ↗
30 sh @ $1351.61
$41K
SELL10b5-1
Sciammas Maurice · EVP, WW Sales & Marketing
Tx Jun 1·Filed Jun 3·EDGAR ↗
30 sh @ $1533.95
$46K
GIFT
Sciammas Maurice · EVP, WW Sales & Marketing
Tx May 29·Filed Jun 2·EDGAR ↗
12,472 sh
—
SELL
Dean Robert W II · Interim CFO
Tx May 26·Filed May 28·EDGAR ↗
22 sh @ $1649.56
$36K
SELL
Zhou Jeff · Director
Tx May 26·Filed May 27·EDGAR ↗
486 sh @ $1680.00
$816K
SELL
Tseng Saria · EVP & General Counsel
Tx May 22·Filed May 27·EDGAR ↗
5,000 sh @ $1586.43
$7.9M
GIFT
Tseng Saria · EVP & General Counsel
Tx May 22·Filed May 27·EDGAR ↗
200 sh
—
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
5,819 sh @ $1467.62
$8.5M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
2,929 sh @ $1503.05
$4.4M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
608 sh @ $1499.46
$912K
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
862 sh @ $1491.48
$1.3M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
6,688 sh @ $1486.76
$9.9M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
5,737 sh @ $1482.51
$8.5M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
4,082 sh @ $1476.96
$6.0M
SELL
Hsing Michael · CEO
Tx May 18·Filed May 20·EDGAR ↗
5,049 sh @ $1472.84
$7.4M

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About MPWR insider trading data

Form 4 is the SEC filing required when an officer, director, or 10% owner of a public company buys or sells the company's stock. By law, these filings must be submitted within two business days of the trade. Tracenotes pulls every Form 4 filing for MPWR from EDGAR, parses it, and surfaces the activity on this page.

What insider buying tells you. Open-market purchases by insiders are widely studied as a meaningful signal. Unlike stock awards (which are compensation, not conviction), an executive spending their own money to buy shares of the company they run is a vote of confidence. Studies have found insider-buying clusters — three or more insiders buying within a short window — outperform the broader market over the following year.

What insider selling tells you. Selling is noisier. Many sales are pre-scheduled under SEC Rule 10b5-1 plans, which let insiders sell on a fixed schedule regardless of company news. We label these "10b5-1" so you can see them. Discretionary sales — sales not tied to a plan — are more meaningful, especially when multiple insiders sell in quick succession.

Tracenotes methodology. We scan EDGAR daily for new Form 4 filings, parse them into individual transactions, and detect clusters when three or more distinct insiders buy or sell within a 14-day window. The data on this page covers the last 12 months. For deeper analysis, Tracenotes also runs language-change detection on 10-K and 10-Q filings — that's our core product.

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Frequently asked questions

What is a Form 4 filing?

Form 4 is the SEC disclosure required when a company insider — an officer, director, or 10% owner — buys or sells the company's stock. By law these filings must be submitted within two business days of the trade.

Is insider buying MPWR always bullish?

Open-market purchases by insiders are widely viewed as a bullish signal because executives are spending their own money. Stock awards and option exercises are part of compensation and don't carry the same weight, which is why we treat them separately on this page.

What is a 10b5-1 trade?

A trade made under SEC Rule 10b5-1, which lets insiders pre-schedule sales weeks or months in advance. These sales execute on a fixed plan regardless of company news, so they're a weaker signal than discretionary sales. We label them with a "10b5-1" tag.

What is an insider cluster?

A cluster is when three or more distinct insiders buy or sell within a 14-day window. Clusters are studied as stronger signals than single trades because multiple people independently reach the same view. We surface active clusters on MONOLITHIC POWER SYSTEMS, INC. (MPWR) when they form.

Where does MPWR insider trading data come from?

Every Form 4 filing for MPWR is sourced directly from SEC EDGAR. Tracenotes scans EDGAR daily, parses each Form 4 into individual transactions, and updates this page within hours of new filings.

Nothing on this page constitutes investment advice. Form 4 data is sourced from SEC EDGAR and provided for research purposes only.

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