Monolithic Power Systems, Inc.
US ˙ NasdaqGS ˙ US6098391054

SecurityMPWR / Monolithic Power Systems, Inc.
InstitutionJanney Montgomery Scott LLC
Latest Disclosed Ownership5,256 shares
Latest Disclosed Value $ 5,747
Janney Montgomery Scott LLC reports 6.72% increase in ownership of MPWR / Monolithic Power Systems, Inc.

On April 22, 2026 - Janney Montgomery Scott LLC filed a 13F-HR form disclosing ownership of 5,256 shares of Monolithic Power Systems, Inc. (US:MPWR) valued at $5,746,648 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 4,925 shares of Monolithic Power Systems, Inc.. This represents a change in shares of 6.72% during the quarter. The current value of the position is $7,784,399 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-04-22 2026-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 5,256 331 6.72 6 25.00 0.0142
2026-02-11 2025-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 4,925 -15,558 -75.96 4 -77.78 0.0102
2025-10-27 2025-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 20,483 -1,863 -8.34 19 12.50 0.0447
2025-07-17 2025-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 22,346 -761 -3.29 16 23.08 0.0427
2025-04-17 2025-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 23,107 -655 -2.76 13 -7.14 0.0380
2025-01-17 2024-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 23,762 -1,230 -4.92 14 -39.13 0.0390
2024-10-29 2024-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 24,992 -653 -2.55 23 9.52 0.0645
2024-07-25 2024-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 25,645 -571 -2.18 21 23.53 0.0642
2024-05-01 2024-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 26,216 27 0.10 18 6.25 0.0528
2024-02-08 2023-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 26,189 22,337 579.88 17 1,500.00 0.0536
2023-11-08 2023-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 3,852 210 5.77 2 0.00 0.0066
2023-07-26 2023-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 3,642 -963 -20.91 2 -50.00 0.0069
2023-04-28 2023-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 4,605 -18,773 -80.30 2 -75.00 0.0094
2023-02-01 2022-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 23,378 2,151 10.13 8 -99.90 0.0322
2022-10-25 2022-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 21,227 159 0.75 7,714 -5.49 0.0331
2022-08-03 2022-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 21,068 1,024 5.11 8,162 -16.16 0.0369
2022-05-04 2022-03-31 13F MP MATERIALS Common Stock 609839105 20,044 1,665 9.06 9,735 7.37 0.0416
2022-01-27 2021-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 18,379 15,604 562.31 9,067 574.13 0.0352
2021-10-29 2021-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 2,775 -927 -25.04 1,345 -2.75 0.0058
2021-07-26 2021-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 3,702 222 6.38 1,383 12.53 0.0061
2021-04-27 2021-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 3,480 109 3.23 1,229 -0.49 0.0060
2021-01-25 2020-12-31 13F MONOLITHIC POWER SYS Common Stock 609839105 3,371 -455 -11.89 1,235 15.42 0.0060
2020-11-06 2020-09-30 13F MONOLITHIC POWER SYS Common Stock 609839105 3,826 -177 -4.42 1,070 12.75 0.0061
2020-07-23 2020-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 4,003 -506 -11.22 949 25.70 0.0060
2020-04-30 2020-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 4,509 4,509 755 0.0060
2016-05-10 2016-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 0 0 0 0.0000
2015-08-04 2015-06-30 13F MONOLITHIC POWER SYS Common Stock 609839105 0 -9,880 -100.00 0 -100.00
2015-05-12 2015-03-31 13F/A-1 MONOLITHIC POWER SYS Common Stock 609839105 9,880 9,880 520 0.0097
2015-04-30 2015-03-31 13F MONOLITHIC POWER SYS Common Stock 609839105 9,880 520
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.