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MPWR Monolithic Power Systems, Inc.

Insider figures are trailing 90 days, open-market Form 4 only. Institutional figures are the latest reported quarter. These windows are not simultaneous.

-$40.7M net selling - trailing 90 days

0 buyers - 4 unique sellers

Historical context: most recent complete month (2026-09) is the 19th percentile of this ticker's monthly net P/S flow over 24 complete months. Lower percentiles are more selling; higher are more buying. P10–P90: -$119.3M to $0.

Institutional activity: not available - insufficient comparable institutions for the latest complete quarter.

open-market Form 4 only - grants, exercises, tax withholding excluded. ~ derived from SEC-reported shares x price.

Insider net $ (monthly)open-market Form 4 only - grants, exercises, tax withholding excluded$500.0M$250.0M$0-$250.0M-$500.0M2024-10 -$12.5M2024-11 -$5.0M2024-12 -$1.5M2025-01 -$2.5M2025-02 -$20.1M2025-03 $02025-04 $02025-05 -$8.6M2025-06 $02025-07 -$4.5M2025-08 -$53.0M2025-09 -$16.1M2025-10 -$21.3M2025-11 -$147.8M2025-12 -$3.5M2026-01 -$3.1M2026-02 -$234.9M2026-03 -$26.0M2026-04 -$22.1M2026-05 -$172.0M2026-06 -$46K2026-07 -$20.2M2026-08 -$367K2026-09 -$40.3MOct 24Dec 24Feb 25Apr 25Jun 25Aug 25Oct 25Dec 25Feb 26Apr 26Jun 26Aug 26~ derived from SEC-reported shares x price. Hatched: excluded (implausible price) or unpriced.

Institutional activity: not available - insufficient comparable institutions for the latest complete quarter.

Who is responsible

Insider Role Net activity Rows
Hsing Michael CEO -~$40.3M 8
DEAN ROBERT W II Interim CFO -~$0.2M 3
CHANG KUO WEI HERBERT — -~$0.1M 2
Sciammas Maurice EVP, WW Sales & Marketing -~$40K 1

Transactions

Date Insider Role Type Shares Price Value
September 28, 2026 Hsing Michael CEO 8 reported sale rows 30000 — ~$40.3M
August 24, 2026 DEAN ROBERT W II Interim CFO S -32 1297.72 ~$42K
August 24, 2026 CHANG KUO WEI HERBERT — S -50 1281.57 ~$64K
August 17, 2026 DEAN ROBERT W II Interim CFO S -6 1413.64 ~$8K
August 11, 2026 CHANG KUO WEI HERBERT — S -50 1420 ~$71K
August 5, 2026 DEAN ROBERT W II Interim CFO S -105 1344.27 ~$0.1M
August 3, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1343.94 ~$40K
July 15, 2026 Sciammas Maurice EVP, WW Sales & Marketing 17 reported sale rows 14950 — ~$20.2M
July 1, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1351.61 ~$41K
June 1, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1533.95 ~$46K
May 27, 2026 Tseng Saria EVP & General Counsel S -7565 1700 ~$12.9M
May 26, 2026 Zhou Jeff — S -486 1680 ~$0.8M
May 26, 2026 DEAN ROBERT W II Interim CFO S -22 1649.56 ~$36K
May 22, 2026 Tseng Saria EVP & General Counsel S -5000 1586.43 ~$7.9M
May 18, 2026 Hsing Michael CEO 13 reported sale rows 40000 — ~$59.3M
May 18, 2026 DEAN ROBERT W II Interim CFO S -4 1563.28 ~$6K
May 15, 2026 Sciammas Maurice EVP, WW Sales & Marketing 8 reported sale rows 12000 — ~$18.7M
May 6, 2026 Xiao Deming EVP, Global Operations 4 reported sale rows 30000 — ~$49.6M
May 6, 2026 Zhou Jeff — S -500 1650 ~$0.8M
May 6, 2026 Elmiger Eugen J — 9 reported sale rows 12000 — ~$19.0M
May 6, 2026 Wynne Eileen — S -335 1582.68 ~$0.5M
May 5, 2026 Zhou Jeff — 2 reported sale rows 1014 — ~$1.6M
May 5, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -380 1583.81 ~$0.6M
May 4, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1588.73 ~$48K
April 8, 2026 Tseng Saria EVP & General Counsel 9 reported sale rows 8843 — ~$11.5M
April 6, 2026 Tseng Saria EVP & General Counsel 8 reported sale rows 7636 — ~$8.9M
April 1, 2026 Tseng Saria EVP & General Counsel 5 reported sale rows 1400 — ~$1.6M
April 1, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1116.44 ~$33K
March 30, 2026 Tseng Saria EVP & General Counsel 8 reported sale rows 25674 — ~$25.9M
March 20, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -30 1095.07 ~$33K
February 12, 2026 Hsing Michael CEO 11 reported sale rows 31560 — ~$36.9M
February 11, 2026 Hsing Michael CEO 10 reported sale rows 33000 — ~$39.2M
February 11, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -200 1179.975 ~$0.2M
February 10, 2026 Hsing Michael CEO 9 reported sale rows 34000 — ~$38.8M
February 9, 2026 Lee Victor K — S -400 1212.16 ~$0.5M
February 6, 2026 Xiao Deming EVP, Global Operations S -22875 1171.1637 ~$26.8M jointly filed
February 6, 2026 Tseng Saria EVP & General Counsel S -22875 1171.1637 ~$26.8M jointly filed
February 6, 2026 BLEGEN THEODORE EVP and CFO S -21725 1171.1637 ~$25.4M
February 6, 2026 Sciammas Maurice EVP, WW Sales & Marketing S -22875 1171.1637 ~$26.8M jointly filed
February 6, 2026 Hsing Michael CEO S -54923 1171.1637 ~$64.3M
February 2, 2026 BLEGEN THEODORE EVP and CFO 11 reported sale rows 2360 — ~$2.7M
January 2, 2026 BLEGEN THEODORE EVP and CFO 10 reported sale rows 2680 — ~$2.5M
January 2, 2026 Lee Victor K — S -600 930.86 ~$0.6M
December 24, 2025 Lee Victor K — 6 reported sale rows 1000 — ~$1.0M
December 1, 2025 BLEGEN THEODORE EVP and CFO 6 reported sale rows 2760 — ~$2.5M
November 26, 2025 Tseng Saria EVP & General Counsel 9 reported sale rows 20000 — ~$18.5M
November 25, 2025 Tseng Saria EVP & General Counsel 18 reported sale rows 19840 — ~$17.9M
November 25, 2025 CHANG KUO WEI HERBERT — S -100 896.97 ~$90K
November 24, 2025 Sciammas Maurice EVP, WW Sales & Marketing S -3976 895.23 ~$3.6M
November 21, 2025 CHANG KUO WEI HERBERT — S -100 873.97 ~$87K
November 19, 2025 Sciammas Maurice EVP, WW Sales & Marketing 24 reported sale rows 35000 — ~$30.8M
November 12, 2025 Hsing Michael CEO 18 reported sale rows 36597 — ~$35.3M
November 11, 2025 Hsing Michael CEO 17 reported sale rows 40000 — ~$38.3M
November 5, 2025 Sciammas Maurice EVP, WW Sales & Marketing S -200 986.81 ~$0.2M
November 3, 2025 BLEGEN THEODORE EVP and CFO 19 reported sale rows 2840 — ~$2.9M
October 24, 2025 Tseng Saria EVP & General Counsel S -1300 1087.62 ~$1.4M
October 16, 2025 Tseng Saria EVP & General Counsel 2 reported sale rows 2812 — ~$2.9M
October 15, 2025 Tseng Saria EVP & General Counsel S -14028 1016.18 ~$14.3M
October 1, 2025 BLEGEN THEODORE EVP and CFO 13 reported sale rows 3000 — ~$2.7M
September 18, 2025 Martinez Carintia — S -1400 900 ~$1.3M
September 18, 2025 Tseng Saria EVP & General Counsel S -14510 914.45 ~$13.3M
September 2, 2025 BLEGEN THEODORE EVP and CFO 6 reported sale rows 1900 — ~$1.5M
August 29, 2025 Elmiger Eugen J — 4 reported sale rows 2500 — ~$2.1M
August 27, 2025 Zhou Jeff — S -193 870 ~$0.2M
August 15, 2025 Hsing Michael CEO 11 reported sale rows 20231 — ~$16.8M
August 13, 2025 Zhou Jeff — S -400 850 ~$0.3M
August 12, 2025 Zhou Jeff — S -200 830 ~$0.2M
August 1, 2025 BLEGEN THEODORE EVP and CFO S -3000 750 ~$2.3M
August 1, 2025 Xiao Deming EVP, Global Operations S -39999 780 ~$31.2M
July 1, 2025 BLEGEN THEODORE EVP and CFO S -6000 750 ~$4.5M
May 13, 2025 CHANG KUO WEI HERBERT — S -50 738 ~$37K
May 12, 2025 Sciammas Maurice EVP, WW Sales & Marketing S -12000 701 ~$8.4M
May 12, 2025 CHANG KUO WEI HERBERT — S -100 698 ~$70K
May 8, 2025 CHANG KUO WEI HERBERT — S -100 650 ~$65K
February 18, 2025 Hsing Michael CEO S -5200 700 ~$3.6M
February 10, 2025 Xiao Deming EVP, Global Operations S -662 717.1006 ~$0.5M jointly filed
February 10, 2025 Tseng Saria EVP & General Counsel S -663 717.1004 ~$0.5M
February 10, 2025 Sciammas Maurice EVP, WW Sales & Marketing S -662 717.1006 ~$0.5M jointly filed
February 10, 2025 Hsing Michael CEO S -2594 717.1 ~$1.9M
February 10, 2025 BLEGEN THEODORE EVP and CFO S -532 717.1007 ~$0.4M
February 7, 2025 Hsing Michael CEO S -11964 700 ~$8.4M
February 7, 2025 Sciammas Maurice EVP, WW Sales & Marketing 4 reported sale rows 7000 — ~$4.9M
January 24, 2025 Hsing Michael CEO S -3636 700 ~$2.5M
December 9, 2024 BLEGEN THEODORE EVP and CFO S -2500 600 ~$1.5M
November 8, 2024 Xiao Deming EVP, Global Operations S -866 765.14 ~$0.7M jointly filed
November 8, 2024 Hsing Michael CEO S -2812 765.15 ~$2.2M
November 8, 2024 BLEGEN THEODORE EVP and CFO S -734 765.15 ~$0.6M
November 8, 2024 Sciammas Maurice EVP, WW Sales & Marketing S -866 765.14 ~$0.7M jointly filed
November 8, 2024 Tseng Saria EVP & General Counsel S -866 765.14 ~$0.7M jointly filed
November 1, 2024 BLEGEN THEODORE EVP and CFO 11 reported sale rows 2150 — ~$1.7M
October 7, 2024 Sciammas Maurice EVP, WW Sales & Marketing 11 reported sale rows 11000 — ~$10.2M
October 1, 2024 BLEGEN THEODORE EVP and CFO 19 reported sale rows 2500 — ~$2.3M