StockCIK 1280452

MONOLITHIC POWER SYSTEMS, INC. (MPWR): Insider Trades and Fund Holdings

In the past 12 months, MONOLITHIC POWER SYSTEMS, INC. insiders reported 0 open-market purchases worth $0 and 5 sales worth $40.5M; 1 of the sales were reported as made under a 10b5-1 trading plan.

0Insider buys, 12 months

$0Bought by insiders, 12 months

$40.5MSold by insiders, 12 months

2Tracked funds holding

Recent insider trades

Open-market purchases (code P) and sales (code S) from Form 4. Grants, option exercises and gifts are not shown. Latest filing: Sep 30, 2026.

Recent MPWR insider trades
Filed	Traded	Insider	Role	Type	Shares	Price ($)	Value	Holding	Filing
Sep 30	Sep 28	Michael HsingCEO	CEO	▼ SELL10b5-1	30,000	1344.97	$40.3M	−3.5%	Form 4 ↗
Aug 26	Aug 24	Robert W. Dean IICFO	CFO	▼ SELL	32	1297.72	$42K	−0.4%	Form 4 ↗
Aug 25	Aug 24	Kuo Wei Herbert ChangDirector	Director	▼ SELL	50	1281.58	$64K	−8.8%	Form 4 ↗
Aug 19	Aug 17	Robert W. Dean IICFO	CFO	▼ SELL	6	1413.67	$8K	−0.1%	Form 4 ↗
Aug 13	Aug 11	Kuo Wei Herbert ChangDirector	Director	▼ SELL	50	1420.00	$71K	−8.1%	Form 4 ↗

Source: SEC Form 4 filings, retrieved Oct 28, 2026. How we read filings

Insiders who traded in the past year

Insider	Role	Bought	Sells	Sold	Latest
Michael Hsing	CEO	$0	1	$40.3M	Sep 30, 2026
Robert W. Dean II	CFO	$0	2	$50K	Aug 26, 2026
Kuo Wei Herbert Chang	Director	$0	2	$135K	Aug 25, 2026

Tracked funds that report MPWR

From each fund's latest 13F. Holdings are as of quarter end and are filed up to 45 days later.

Fund	Quarter	Shares	Value	% of portfolio	Change
Renaissance Technologies	Q2 2026	63,066	$87.2M	0.12%	▲ New
Bridgewater Associates	Q2 2026	3,096	$4.28M	0.02%	▼ −74.1%

Source: SEC Form 13F-HR filings, retrieved Oct 28, 2026. How we read filings

Reading these numbers

Insiders sell for many reasons: taxes, diversification, a house. Purchases with their own money are rarer and are usually read as more informative. A Form 4 is due within two business days of the trade. How to read a Form 4 →