2026-10-02 · MPWR
MPWR +6.1%: an unusually large move for this stock
MONOLITHIC POWER SYSTEMS, INC. moved 4.5 points more than its sector, on 0.3× its usual volume.
The story in plain words
Friday, October 2, 2026. MPWR +6.1%: an unusually large move for this stock. MONOLITHIC POWER SYSTEMS, INC. moved 4.5 points more than its sector, on 0.3× its usual volume.
What the data shows for Monolithic Power Systems (MPWR): MPWR +6.1% today. Its sector fund (XLK) +1.5% today. S&P 500 (SPY) +1.0% today.
Worked out from that data: 4.5 points more than its sector. Volume 0.3× its 20-day average. Bigger than 93% of its daily moves over the past 250 trading days.
Possible contributors. These line up in time with the move; they are not confirmed causes: News: “These S&P500 stocks are gapping in today's session” (Published around the move. Timing only, not a confirmed cause). News: “Are You Overpaying For Vicor Stock Versus Its Rivals?” (Published around the move. Timing only, not a confirmed cause).
About the company: Monolithic Power Systems trades as MPWR and is part of the S&P 500, in the Information Technology sector (Semiconductors), headquartered in Kirkland, Washington, founded in 1997.
This is one of CookieStocks’ daily stock stories about unusually large one-day price moves in S&P 500 stocks, measured against each stock’s own history, its sector and its usual volume. Stories are found automatically each trading day from market data and SEC filings, and every claim is labelled as observed, calculated or a possible contributor. Statistics only, not investment advice.
Prove it
Every claim on the graphic, labelled: observed (straight from the data), calculated (worked out from it), or possible contributor (lines up in time, not a confirmed cause).
- OBSERVEDMPWR +6.1% todayOct 2, 2026, 11:05 AM ET
- OBSERVEDIts sector fund (XLK) +1.5% todayOct 2, 2026, 11:05 AM ET
- CALCULATED4.5 points more than its sectorHow: stock return − sector fund return · Oct 2, 2026, 11:05 AM ET
- OBSERVEDS&P 500 (SPY) +1.0% todayOct 2, 2026, 11:05 AM ET
- CALCULATEDVolume 0.3× its 20-day averageHow: today’s volume ÷ average of the last 20 days · Oct 2, 2026, 11:05 AM ET
- CALCULATEDBigger than 93% of its daily moves over the past 250 trading daysHow: share of past daily moves smaller in size · Oct 2, 2026, 11:05 AM ET
- POSSIBLE CONTRIBUTORNews: “These S&P500 stocks are gapping in today's session”Published around the move. Timing only, not a confirmed cause. · Oct 2, 2026, 10:35 AM ET
- POSSIBLE CONTRIBUTORNews: “Are You Overpaying For Vicor Stock Versus Its Rivals?”Published around the move. Timing only, not a confirmed cause. · Oct 1, 2026, 2:26 PM ET
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Statistics only, not investment advice. Past moves don’t predict future ones. Data as of Oct 2, 2026, 11:05 AM ET.