Stock Trading Canary

United States · SEC Form 4 · Snapshot date: 2026-10-18 · Built: 2026-10-18 · 中文

← United States · Coverage record

US · SEC FORM 4

MONOLITHIC POWER SYSTEMS INC

MPWR · Nasdaq · CIK 0001280452 · Technology · Semiconductors

INSIDER SIGNAL

No active buy signal

0 qualifying P purchase groups
in the current 180-day scoring window

87 Form 4 transaction lines observed in the same window
79 sales · 8 option, withholding, award, gift or other lines

Last qualifying purchaseNo qualifying purchase is present in the local Form 4 history.

WHY NO ACTIVE SIGNAL?

Purchase activityNone
Recent buyingNone
Recent salesHigh
Buy signal statusInactive
Score anatomy

No score is calculated because there is no qualifying purchase in the active window. Unavailable inputs are not treated as zero or as a bearish signal.

ClusterNot calculated
Purchase sizeNot calculated
RoleNot calculated
RecencyNot calculated
ConvictionNot calculated

Why is there no score?

  • No qualifying open-market purchase supplies cluster, size, role, recency or conviction inputs.
  • Sales and other Form 4 activity remain visible as context and do not create a negative score.

Sales and other Form 4 activity are shown separately and do not create a negative buy signal. Absence of buying is not scored as bearish.

Insider activity timeline

Owner lanes show the latest 180 days. Symbol shape identifies the transaction type; sales remain context only.

AprMayJunJulAugSepOct
Sciammas MauriceEVP, WW Sales & Marketing
▼▼○▼○▼▼▼▼○
DEAN ROBERT W IIInterim CFO
○▼▼○▼▼○▼
Tseng SariaEVP & General Counsel
○▼▼○
Zhou JeffDirector
▼▼▼
Hsing MichaelCEO
▼▼
CHANG KUO WEI HERBERTDirector
▼▼
● Purchase▼ Sale○ Other

Showing the six most active owners; 3 additional owner(s) remain in Form 4 evidence.

Purchase breadth, concentration & cluster buying

These modules activate when qualifying purchases enter the 180-day research window.

SIGNAL HISTORY

No recorded active-signal snapshot

Scores are archived only when the company qualifies for a published US buy-signal snapshot.—

Recent Form 4 activity

0Purchases
306Sales
32Other Form 4 lines
85SEC filings · 365 days
BUYING0 qualifying P line(s) · 180 days
SELLING79 sale line(s) · context only
OTHER8 exercise / withholding / award / gift / other lines
10b5-1 / PLANNEDNot assessed

P is an open-market or private purchase. S is a sale. M, F, A and G usually describe exercises, tax withholding, awards and gifts. These categories remain visually separate.

Market context

Market context has not been captured for this ticker yet. The daily market-context job processes the US universe in rotating batches.

Short interest

Short interest is external context reported to FINRA by broker-dealers. It does not affect the Insider Signal.

Shares short
1,858,921
Previous report
1,906,839
Avg daily volume
799,004
Days to cover
2.3

FINRA settlement date: 2026-09-30 · Captured 2026-10-12 · FINRA equity short interest ↗. A share count, published about a week after each of two settlement dates a month; not a percentage of shares outstanding.

Historical equity purchases

No qualifying code P equity purchase is present in the local Form 4 history.

Form 4 evidence

338 transaction lines in the latest 365-day window; 1,608 in local history.

DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-28Hsing MichaelSale (S)Common Stock30,000USD 1,344.97USD 40,349,047SEC filing ↗
2026-08-31Tseng SariaGift (G)Common Stock2,000USD 0.00USD 0SEC filing ↗
2026-08-24DEAN ROBERT W IISale (S)Common Stock32USD 1,297.72USD 41,527SEC filing ↗
Show recent Form 4 evidence (30 grouped rows)
DateOwnerTypeSecuritySharesAvg. priceApprox. valueSource
2026-09-28Hsing MichaelSale (S)Common Stock30,000USD 1,344.97USD 40,349,047SEC filing ↗
2026-08-31Tseng SariaGift (G)Common Stock2,000USD 0.00USD 0SEC filing ↗
2026-08-24DEAN ROBERT W IISale (S)Common Stock32USD 1,297.72USD 41,527SEC filing ↗
2026-08-24DEAN ROBERT W IIJ (J)Common Stock5USD 0.00USD 0SEC filing ↗
2026-08-24CHANG KUO WEI HERBERTSale (S)Common Stock50USD 1,281.57USD 64,078SEC filing ↗
2026-08-17DEAN ROBERT W IISale (S)Common Stock6USD 1,413.64USD 8,482SEC filing ↗
2026-08-11CHANG KUO WEI HERBERTSale (S)Common Stock50USD 1,420.00USD 71,000SEC filing ↗
2026-08-05DEAN ROBERT W IISale (S)Common Stock105USD 1,344.27USD 141,148SEC filing ↗
2026-08-04Sciammas MauriceGift (G)Common Stock25,000USD 0.00USD 0SEC filing ↗
2026-08-03Sciammas MauriceSale (S)Common Stock30USD 1,343.94USD 40,318SEC filing ↗
2026-07-25DEAN ROBERT W IIAward / grant (A)Common Stock1,359USD 0.00USD 0SEC filing ↗
2026-07-15Sciammas MauriceSale (S)Common Stock15,000USD 1,349.73USD 20,245,937SEC filing ↗
2026-07-01Sciammas MauriceSale (S)Common Stock30USD 1,351.61USD 40,548SEC filing ↗
2026-06-01Sciammas MauriceSale (S)Common Stock30USD 1,533.95USD 46,018SEC filing ↗
2026-05-29Sciammas MauriceGift (G)Common Stock12,472USD 0.00USD 0SEC filing ↗
2026-05-27Tseng SariaSale (S)Common Stock7,565USD 1,700.00USD 12,860,500SEC filing ↗
2026-05-26DEAN ROBERT W IISale (S)Common Stock22USD 1,649.56USD 36,290SEC filing ↗
2026-05-26Zhou JeffSale (S)Common Stock486USD 1,680.00USD 816,480SEC filing ↗
2026-05-22Tseng SariaSale (S)Common Stock5,000USD 1,586.43USD 7,932,150SEC filing ↗
2026-05-22Tseng SariaGift (G)Common Stock200USD 0.00USD 0SEC filing ↗
2026-05-18Hsing MichaelSale (S)Common Stock40,000USD 1,482.75USD 59,310,169SEC filing ↗
2026-05-18DEAN ROBERT W IISale (S)Common Stock4USD 1,563.28USD 6,253SEC filing ↗
2026-05-15Sciammas MauriceSale (S)Common Stock12,000USD 1,561.40USD 18,736,850SEC filing ↗
2026-05-13Sciammas MauriceGift (G)Common Stock1,563USD 0.00USD 0SEC filing ↗
2026-05-13DEAN ROBERT W IIJ (J)Common Stock2,156USD 0.00USD 0SEC filing ↗
2026-05-06Xiao DemingSale (S)Common Stock30,000USD 1,654.55USD 49,636,560SEC filing ↗
2026-05-06Wynne EileenSale (S)Common Stock335USD 1,582.68USD 530,198SEC filing ↗
2026-05-06Elmiger Eugen JSale (S)Common Stock12,000USD 1,584.96USD 19,019,482SEC filing ↗
2026-05-06Zhou JeffSale (S)Common Stock500USD 1,650.00USD 825,000SEC filing ↗
2026-05-05Zhou JeffSale (S)Common Stock1,014USD 1,587.06USD 1,609,283SEC filing ↗

Multiple price lines in one filing are grouped and share-weighted. Price and value are blank when a grouped filing line lacks price evidence.

Snapshot & identity

Snapshot date2026-10-18
Ranking versionUS-v1.2
Data qualityPASS ELIGIBLE · —
TickerMPWR
CIK0001280452
SectorTechnology
IndustrySemiconductors Yahoo Finance
SEC SIC3674 Semiconductors & Related Devices
ExchangeNasdaq

Data coverage

Local Form 4 history1,608 transaction lines from 2020-01-07 to 2026-09-28
0 P purchase lines · 1,436 S sale lines · 172 other lines
SEC company submissionsOpen SEC filings ↗

Local ledger as of 2026-10-18. Mapping status is an audit field and does not erase SEC filing evidence.