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Monolithic Power Systems, Inc. planned insider sales

In the last twelve months insiders at Monolithic Power Systems, Inc. filed 54 Form 144 notices of planned sales, 623,016 shares worth $740.1 million at the time of filing, from 21 sellers. The latest, filed 28 September 2026: Michael Hsing (officer, director), 30,000 shares worth $40.3 million, planned for around 28 September 2026 through Morgan Stanley Smith Barney LLC Executive Financial Services.

FiledSellerRelationshipSharesValuePlanned saleSold, per Form 4BrokerHow acquiredFiling
28 September 2026Michael HsingOfficer, Director30,000$40.3 million28 September 202630,000 shares from 28 September 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesEmployee Stock Purchase Plan; Performance SharesForm 144
24 August 2026Dean Robert W IiOfficer32$41,52724 August 202632 shares from 24 August 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesTime-based restricted stock unitsForm 144
17 August 2026Dean Robert W IiOfficer6$8,12817 August 20266 shares from 17 August 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesTime-based restricted stock unitsForm 144
11 August 2026Kuo Wei ChangDirector100$142,00011 August 2026100 shares from 11 August 2026UBS Financial Services IncRSUForm 144
5 August 2026Robert DeanOfficer105$141,1485 August 2026105 shares from 5 August 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
15 July 2026Maurice SciammasOfficer15,000$20.2 million15 July 202615,030 shares from 15 July 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesRestricted StockForm 144
1 June 2026Theodore Bernhard BlegenOfficer3,001$4.6 million1 June 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
28 May 2026Saria TsengOfficer7,565$12.9 million27 May 20267,565 shares from 27 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
26 May 2026Dean Robert W IiOfficer22$35,88226 May 202622 shares from 26 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesTime-based restricted stock unitsForm 144
26 May 2026Jeff ZhouDirector486$816,48026 May 2026486 shares from 26 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesRestricted StockForm 144
22 May 2026Saria TsengOfficer5,000$7.9 million22 May 20265,000 shares from 22 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
18 May 2026Dean Robert W IiOfficer4$6,25318 May 20264 shares from 18 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesTime-based restricted stock unitsForm 144
18 May 2026Michael HsingOfficer, Director40,000$59.3 million18 May 202640,000 shares from 18 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
15 May 2026Maurice SciammasOfficer12,000$18.7 million15 May 202612,060 shares from 15 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
6 May 2026Eileen WynneDirector335$530,1966 May 2026335 shares from 6 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesRestricted StockForm 144
6 May 2026Jeff ZhouDirector500$825,0006 May 20261,514 shares from 5 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesRestricted StockForm 144
6 May 2026Elmiger Eugen JDirector12,000$19.8 million7 May 202612,000 shares from 6 May 2026Luzerner Kantonalbank AGRestricted Stock UnitsForm 144
6 May 2026Deming XiaoOfficer30,000$49.6 million6 May 202630,000 shares from 6 May 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
5 May 2026Rosalind SciammasMember of immediate family of any of the foregoing400$600,0005 May 2026No matching Form 4 saleUBS Financial Services IncGRAT DistributionForm 144
5 May 2026Jeff ZhouDirector1,014$1.6 million5 May 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesRestricted StockForm 144
1 May 2026Theodore Bernhard BlegenOfficer3,000$4.6 million1 May 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
8 April 2026Saria TsengOfficer8,964$11.7 million8 April 20268,963 shares from 8 April 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
6 April 2026Saria TsengOfficer7,636$8.9 million6 April 20267,636 shares from 6 April 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
1 April 2026Saria TsengOfficer1,400$1.6 million1 April 20261,400 shares from 1 April 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
1 April 2026Theodore Bernhard BlegenOfficer3,000$3.3 million1 April 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
30 March 2026Saria TsengOfficer25,674$25.9 million30 March 202625,674 shares from 30 March 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
20 March 2026Sciammas MauriceOfficer120$131,33320 March 2026470 shares from 20 March 2026UBS Financial Services, Inc.GiftForm 144
2 March 2026Theodore Bernhard BlegenOfficer3,000$3.3 million2 March 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
12 February 2026Michael HsingOfficer, Director33,000$38.7 million12 February 202666,000 shares from 11 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
11 February 2026Michael HsingOfficer, Director33,000$39.2 million11 February 202634,000 shares from 10 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
10 February 2026The Sciammas Trust DTD 06/08/2018Member of immediate family of any of the foregoing200$240,00010 February 2026No matching Form 4 saleUBS Financial Services IncGRAT DistributionForm 144
10 February 2026Michael HsingOfficer, Director34,000$38.8 million10 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
6 February 2026Blegen TheodoreOfficer995$1.2 million6 February 202621,725 shares from 6 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
6 February 2026Tseng SariaOfficer1,286$1.5 million6 February 202622,875 shares from 6 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
6 February 2026Xiao DemingOfficer1,286$1.5 million6 February 202622,875 shares from 6 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
6 February 2026Sciammas MauriceOfficer1,286$1.5 million6 February 202623,075 shares from 6 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
6 February 2026Hsing MichaelOfficer, Director3,082$3.6 million6 February 202654,923 shares from 6 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
4 February 2026Blegen TheodoreOfficer20,730$24.1 million4 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
4 February 2026Sciammas MauriceOfficer21,590$25.1 million4 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
4 February 2026Tseng SariaOfficer21,590$25.1 million4 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
4 February 2026Xiao DemingOfficer21,590$25.1 million4 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
4 February 2026Hsing MichaelOfficer, Director51,841$60.4 million4 February 2026No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance-based restricted stock unitsForm 144
2 February 2026Theodore Bernhard BlegenOfficer3,000$3.4 million2 February 20263,000 shares from 2 February 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
2 January 2026Theodore Bernhard BlegenOfficer3,000$2.8 million2 January 20263,000 shares from 2 January 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
29 December 2025Victor LeeDirector2,000$1.9 million24 December 20251,000 shares from 2 January 2026Morgan Stanley Smith Barney LLC Executive Financial ServicesRestricted Stock UnitsForm 144
1 December 2025Bernie BlegenOfficer3,000$2.7 million1 December 2025No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
26 November 2025Saria TsengOfficer20,000$18.5 million26 November 202540,000 shares from 25 November 2025Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
25 November 2025Saria TsengOfficer20,000$18.1 million25 November 2025No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
24 November 2025Maurice SciammasOfficer3,976$3.6 million24 November 20253,976 shares from 24 November 2025Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
21 November 2025Kuo Wei ChangDirector200$169,24021 November 2025200 shares from 21 November 2025UBS Financial Services IncRSUForm 144
19 November 2025Maurice SciammasOfficer35,000$30.8 million19 November 202535,000 shares from 19 November 2025Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
12 November 2025Hsing MichaelOfficer, Director7,000$6.7 million12 November 2025No matching Form 4 saleUBS Financial Services IncRestricted Stock UnitsForm 144
12 November 2025Michael HsingOfficer, Director30,000$29.0 million12 November 2025No matching Form 4 saleMorgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
12 November 2025Michael HsingOfficer, Director40,000$38.3 million11 November 202577,000 shares from 11 November 2025Morgan Stanley Smith Barney LLC Executive Financial ServicesPerformance SharesForm 144
A Form 144 is the notice an insider files with the SEC before selling restricted or control shares over the Rule 144 thresholds; it says what may be sold, not what was.
Read moreValue is the filer's own aggregate market value. Sold, per Form 4: the same seller's open-market sales on Form 4 from the notice's date to 90 days after, added up, as they appear on the insiders page; a holder who files no Form 4, such as some large holders, never shows one. What is a Form 144?