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MPWR in the 13F filings

Monolithic PWR Sys Inc · CUSIP 609839105

Sector · SemiconductorsTheme · AI infrastructure and semiconductors· L3VLUP-definedTheme · Semiconductors
Quarter
Q3 2026 · early filersQ2 2026Q1 2026Q4 2025Q3 2025Q2 2025Q1 2025Q4 2024Q3 2024Q2 2024Q1 2024Q4 2023
Quarter end
31 Mar 2026
the date the book describes
Filed
27 Oct 2026
latest of these filings; the earliest 12 May 2026
Managers listing it
28
at least, of 95 tracked, among listed positions
Comparable managers
91
filed both Q4 2025 and Q1 2026; 11 listed it in both
Shares listed
9,612,773
combined, among listed positions
Reported value
$10.5bn
combined, at the quarter end

AllianceBernstein LP. Values in this filing are at the previous quarter end's prices; its share count is the quarter end's.

Among the 91 comparable managers: 15 buyers (opened or added shares) and 15 sellers (trimmed or exited), at least, among listed positions. Their net change in shares was -212,012.

Managers listing MPWR in Q1 2026

Share of 13F value is the position’s reported value over everything the manager reported that quarter. The share change is against Q4 2025, and only where both filings list the position. A rise in value with no rise in shares is the price, not buying.

28 of 28 holders

ActionFiling
Fidelity (FMR LLC)4,400,831$4.8bn0.25%Added+423,82315 May 2026 (the filing on sec.gov)
Invesco Ltd2,515,987$2.8bn0.27%Added+5,00712 May 2026 (the filing on sec.gov)
T. Rowe Price Associates Inc1,262,954$1.4bn0.16%Trimmed-428,44015 May 2026 (the filing on sec.gov)
MFS Investment Management567,769$621m0.21%Trimmed-2,95014 May 2026 (the filing on sec.gov)
Wellington Management Group LLP250,511$274m0.05%Trimmed-134,25915 May 2026 (the filing on sec.gov)
Artisan Partners LP150,873$165m0.26%Trimmed-2,98913 May 2026 (the filing on sec.gov)
Neuberger Berman Group LLC150,107$164m0.12%Trimmed-31,59927 Oct 2026 (the filing on sec.gov)
AllianceBernstein LP124,647$113munder 0.1%Trimmed-9,98415 May 2026 (the filing on sec.gov)
AQR Capital Management LLC38,360$40munder 0.1%Trimmed-7,91815 May 2026 (the filing on sec.gov)
Squarepoint Ops LLC32,420$35munder 0.1%Added+30,87015 May 2026 (the filing on sec.gov)
Susquehanna International Group LLP29,963$33munder 0.1%Trimmed-26,89215 May 2026 (the filing on sec.gov)
Freestone Grove Partners LP15,015$16m0.12%Added+7,48615 May 2026 (the filing on sec.gov)
Citadel Advisors LLC13,512$15munder 0.1%Added+2,28315 May 2026 (the filing on sec.gov)
Two Sigma Investments LP12,018$13munder 0.1%Newnew15 May 2026 (the filing on sec.gov)
Bridgewater Associates LP11,942$13m0.06%Added+9,07115 May 2026 (the filing on sec.gov)
Janus Henderson Group Ltd7,374$8.1munder 0.1%Added+12818 May 2026 (the filing on sec.gov)
Marshall Wace LLP6,732$7.4munder 0.1%Newnew15 May 2026 (the filing on sec.gov)
Man Group PLC6,508$7.1munder 0.1%Trimmed-20,42815 May 2026 (the filing on sec.gov)
Jane Street Group LLC5,083$5.6munder 0.1%Added+59612 May 2026 (the filing on sec.gov)
Holocene Advisors LP2,303$2.5munder 0.1%Newnew15 May 2026 (the filing on sec.gov)
Woodline Partners LP1,869$2.0munder 0.1%Trimmed-77115 May 2026 (the filing on sec.gov)
Acadian Asset Management LLC1,545$1.7munder 0.1%Added+93413 May 2026 (the filing on sec.gov)
Winton Group Ltd1,541$1.7m0.06%Added+9312 May 2026 (the filing on sec.gov)
D. E. Shaw & Co.1,217$1.3munder 0.1%Trimmed-13115 May 2026 (the filing on sec.gov)
Balyasny Asset Management LLC795$869kunder 0.1%Trimmed-2215 May 2026 (the filing on sec.gov)
Page 1 of 2

Largest increases and reductions, by shares

Q4 2025 to Q1 2026, among managers that listed it in both quarters or opened it.

Increases

Reductions

New positions and exits

At least these many: a manager is shown exiting only where its own filing shows the position gone.

New (4)

Exited (2)

Ownership over time

Every quarter on file. A quarter-end value moves with the price as well as with the shares held; buyers and sellers count comparable managers, by shares.
23 in Q3 2024 to 21 in Q2 2026

Tracked managers listing it, at least.

01020302014201620182020202220242026
the quarter shown share split complete books; unmarked quarters rest on listed positionsClick a quarter to open it.
MPWR by quarter
QuarterHoldersReported valueBuyersSellers
Q2 20132$59mn.a.n.a.
Q3 20134$87mn.a.n.a.
Q4 20133$69mn.a.n.a.
Q1 20144$105mn.a.n.a.
Q2 20144$117mn.a.n.a.
Q3 20146$128mn.a.n.a.
Q4 20146$151mn.a.n.a.
Q1 20152$57mn.a.n.a.
Q2 20152$70mn.a.n.a.
Q3 20154$55mn.a.n.a.
Q4 20154$107mn.a.n.a.
Q1 20165$134mn.a.n.a.
Q2 20162$50mn.a.n.a.
Q3 20163$353mn.a.n.a.
Q4 20163$65mn.a.n.a.
Q1 20174$187mn.a.n.a.
Q2 20174$118mn.a.n.a.
Q3 20174$186mn.a.n.a.
Q4 20175$168mn.a.n.a.
Q1 20187$194mn.a.n.a.
Q2 20189$270mn.a.n.a.
Q3 201810$281mn.a.n.a.
Q4 20187$428mn.a.n.a.
Q1 20199$506mn.a.n.a.
Q2 20199$556mn.a.n.a.
Q3 201911$907mn.a.n.a.
Q4 201910$1.1bnn.a.n.a.
Q1 202013$1.2bnn.a.n.a.
Q2 202014$1.7bnn.a.n.a.
Q3 202021$2.0bnn.a.n.a.
Q4 202015$2.4bnn.a.n.a.
Q1 202113$2.1bnn.a.n.a.
Q2 202116$2.1bnn.a.n.a.
Q3 202114$3.2bnn.a.n.a.
Q4 202118$3.5bnn.a.n.a.
Q1 202216$3.7bnn.a.n.a.
Q2 202220$2.8bnn.a.n.a.
Q3 202224$3.4bnn.a.n.a.
Q4 202222$4.1bnn.a.n.a.
Q1 202324$5.8bnn.a.n.a.
Q2 202316$5.9bnn.a.n.a.
Q3 202316$5.0bnn.a.n.a.
Q4 202319$6.4bn1110
Q1 202419$6.7bn912
Q2 202417$8.0bn712
Q3 202423$8.9bn1410
Q4 202417$5.1bn118
Q1 202518$5.6bn117
Q2 202513$6.4bn611
Q3 202516$8.0bn108
Q4 202512$8.8bn1220
Q1 202612$10.3bn1515
Q2 202621$14.1bn2712

Compare with…

Holders over time, buyers and sellers, and the managers holding both, side by side for up to four stocks.

MPWR and NVDA →MPWR and AVGO →MPWR and MU →Choose a stock to compare with MPWR →

How much of the picture this is

A 13F is a manager’s long US-listed equity book at a quarter end, filed up to 45 days later. It shows no shorts, cash, bonds or performance, and it is never today’s portfolio. Large books are listed to their largest positions, so a manager missing from this table may still hold a small position below that line. These are 95 tracked managers, not the institutional market.

Which funds own MPWR, latest filings →Back to the 13F Explorer →