Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionM&t Bank Corp
Latest Disclosed Ownership2,710 shares
Latest Disclosed Value $ 2,962,980
M&t Bank Corp reports 1.53% decrease in ownership of MPWR / Monolithic Power Systems, Inc.

On May 12, 2026 - M&t Bank Corp filed a 13F-HR form disclosing ownership of 2,710 shares of Monolithic Power Systems, Inc. (MX:MPWR) valued at $2,962,980 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on January 30, 2026 disclosing 2,752 shares of Monolithic Power Systems, Inc.. This represents a change in shares of -1.53% during the quarter.

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)
2026-05-12 2026-03-31 13F MONOLITHIC PWR SYS COM 609839105 2,710 -42 -1.53 2,963 18.77 0.0024
2026-01-30 2025-12-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 2,752 527 23.69 2,494 21.84 0.0080
2026-01-28 2025-12-31 13F MONOLITHIC PWR SYS COM 609839105 12,578 10,353 459 0.0003
2025-11-14 2025-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,225 -439 -16.48 2,048 5.14 0.0069
2025-08-13 2025-06-30 13F MONOLITHIC PWR SYS COM 609839105 2,664 58 2.23 1,948 28.86 0.0067
2025-04-30 2025-03-31 13F MONOLITHIC PWR SYS COM 609839105 2,606 -515 -16.50 1,511 -18.19 0.0055
2025-02-06 2024-12-31 13F MONOLITHIC PWR SYS COM 609839105 3,121 254 8.86 1,847 -30.28 0.0062
2024-11-19 2024-09-30 13F/A-1 MONOLITHIC PWR SYS COM 609839105 2,867 -463 -13.90 2,650 -3.14 0.0087
2024-11-15 2024-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,867 -463 2,650 0.0016
2024-07-31 2024-06-30 13F MONOLITHIC PWR SYS COM 609839105 3,330 -152 -4.37 2,735 15.99 0.0093
2024-05-07 2024-03-31 13F MONOLITHIC PWR SYS COM 609839105 3,482 -215 -5.82 2,359 1.11 0.0082
2024-02-06 2023-12-31 13F MONOLITHIC PWR SYS COM 609839105 3,697 240 6.94 2,332 46.02 0.0086
2023-11-02 2023-09-30 13F MONOLITHIC PWR SYS COM 609839105 3,457 -98 -2.76 1,597 -16.82 0.0064
2023-08-09 2023-06-30 13F MONOLITHIC PWR SYS COM 609839105 3,555 -394 -9.98 1,920 -2.83 0.0072
2023-05-11 2023-03-31 13F MONOLITHIC PWR SYS COM 609839105 3,949 434 12.35 1,976 59.10 0.0077
2023-02-13 2022-12-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 3,515 -741 -17.41 1,243 -19.72 0.0050
2023-02-13 2022-12-31 13F MONGODB CL A 609839105 3,730 -526 1,137 0.0046
2022-11-17 2022-09-30 13F/A-1 MONOLITHIC PWR SYS COM 609839105 4,256 38 0.90 1,547 -1.15 0.0069
2022-11-14 2022-09-30 13F MONOLITHIC PWR SYS COM 609839105 4,256 38 1,515 0.0013
2022-08-05 2022-06-30 13F MONOLITHIC PWR SYS COM 609839105 4,218 1,121 36.20 1,565 3.99 0.0074
2022-05-09 2022-03-31 13F MONOLITHIC PWR SYS COM 609839105 3,097 91 3.03 1,505 1.55 0.0066
2022-02-07 2021-12-31 13F MONOLITHIC PWR SYS COM 609839105 3,006 70 2.38 1,482 4.07 0.0062
2021-10-28 2021-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,936 383 15.00 1,424 49.27 0.0064
2021-08-13 2021-06-30 13F MONOLITHIC PWR SYS COM 609839105 2,553 497 24.17 954 31.40 0.0042
2021-05-06 2021-03-31 13F MONOLITHIC PWR SYS COM 609839105 2,056 -527 -20.40 726 -23.17 0.0031
2021-02-12 2020-12-31 13F MONOLITHIC PWR SYS COM 609839105 2,583 410 18.87 945 55.43 0.0041
2020-11-06 2020-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,173 288 15.28 608 36.32 0.0030
2020-07-29 2020-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,885 223 13.42 446 60.43 0.0024
2020-05-14 2020-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,662 -298 -15.20 278 -20.34 0.0016
2020-02-07 2019-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,960 442 29.12 349 47.88 0.0016
2019-11-12 2019-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,518 -88 -5.48 236 8.26 0.0012
2019-08-12 2019-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,606 -69 -4.12 218 -3.96 0.0011
2019-05-15 2019-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,675 -129 -7.15 227 7.58 0.0012
2019-02-01 2018-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,804 101 5.93 211 -1.40 0.0012
2018-11-09 2018-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,703 1,703 214 0.0011
2015-11-13 2015-09-30 13F MONOLITHIC PWR SYS COM 609839105 0 -8,070 -100.00 0 -100.00
2015-08-14 2015-06-30 13F MONOLITHIC PWR SYS COM 609839105 8,070 3,923 94.60 409 87.61 0.0025
2015-05-14 2015-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,147 -213 -4.89 218 0.46 0.0014
2015-02-12 2014-12-31 13F MONOLITHIC PWR SYS COM 609839105 4,360 -747 -14.63 217 -3.56 0.0014
2014-11-14 2014-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,107 5,107 225 0.0016
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.