Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionAmeriprise Financial Inc
Latest Disclosed Ownership119,423 shares
Latest Disclosed Value $ 130,583,900
Ameriprise Financial Inc reports 10.64% decrease in ownership of MPWR / Monolithic Power Systems, Inc.

On May 15, 2026 - Ameriprise Financial Inc filed a 13F-HR form disclosing ownership of 119,423 shares of Monolithic Power Systems, Inc. (MX:MPWR) valued at $130,583,900 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 133,637 shares of Monolithic Power Systems, Inc.. This represents a change in shares of -10.64% 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)
2026-05-15 2026-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 119,423 -14,214 -10.64 130,584 7.80 0.0056
2026-02-17 2025-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 133,637 -26,567 -16.58 121,133 -17.88 0.0274
2025-11-14 2025-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 160,204 -58,773 -26.84 147,516 -7.90 0.0339
2025-08-14 2025-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 218,977 41,706 23.53 160,166 55.77 0.0395
2025-05-14 2025-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 177,271 -8,192 -4.42 102,821 -6.30 0.0278
2025-02-14 2024-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 185,463 -8,735 -4.50 109,731 -39.02 0.0282
2024-11-14 2024-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 194,198 3,111 1.63 179,955 14.61 0.0461
2024-08-14 2024-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 191,087 64,826 51.34 157,014 83.60 0.0425
2024-05-15 2024-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 126,261 -13,800 -9.85 85,521 -3.21 0.0235
2024-02-14 2023-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 140,061 28,415 25.45 88,356 71.27 0.0265
2023-11-14 2023-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 111,646 -38,961 -25.87 51,589 -36.60 0.0169
2023-08-14 2023-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 150,607 -123,974 -45.15 81,367 -40.83 0.0255
2023-05-22 2023-03-31 13F/A-1 MONOLITHIC POWER SYSTEMS COM 609839105 274,581 2,990 1.10 137,516 43.19 0.0451
2023-05-15 2023-03-31 13F MONGODB CONV BND 609839105 274,581 2,990 137,516 0.0083
2023-02-14 2022-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 271,591 49,630 22.36 96,038 18.94 0.0329
2022-11-14 2022-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 221,961 174,908 371.73 80,742 350.52 0.0299
2022-08-15 2022-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 47,053 1,712 3.78 17,922 -16.27 0.0063
2022-05-16 2022-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 45,341 1,477 3.37 21,405 2.27 0.0063
2022-02-14 2021-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 43,864 18,896 75.68 20,930 72.92 0.0058
2021-11-15 2021-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 24,968 -61,730 -71.20 12,104 -62.46 0.0039
2021-08-16 2021-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 86,698 -3,899 -4.30 32,241 0.75 0.0100
2021-05-17 2021-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 90,597 -60,680 -40.11 32,000 -42.24 0.0106
2021-02-12 2020-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 151,277 -1,018 -0.67 55,399 30.10 0.0196
2020-11-16 2020-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 152,295 -3,880 -2.48 42,581 15.00 0.0173
2020-08-14 2020-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 156,175 1,894 1.23 37,027 43.30 0.0159
2020-05-15 2020-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 154,281 -13,669 -8.14 25,839 -13.58 0.0136
2020-02-14 2019-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 167,950 -56,630 -25.22 29,901 -14.94 0.0124
2019-11-14 2019-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 224,580 -13,919 -5.84 35,154 8.54 0.0158
2019-08-14 2019-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 238,499 -98,282 -29.18 32,389 -29.02 0.0145
2019-05-15 2019-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 336,781 -257,569 -43.34 45,628 -33.96 0.0210
2019-02-14 2018-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 594,350 -125,449 -17.43 69,096 -23.53 0.0346
2018-11-14 2018-09-30 13F MONOLITHIC PWR SYS I COM 609839105 719,799 -743 -0.10 90,359 -6.18 0.0316
2018-08-14 2018-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 720,542 -126,548 -14.94 96,312 -1.78 0.0426
2018-05-14 2018-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 847,090 657,921 347.80 98,054 361.28 0.0444
2018-02-12 2017-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 189,169 -6,114 -3.13 21,257 2.16 0.0097
2017-11-07 2017-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 195,283 6,424 3.40 20,808 14.29 0.0099
2017-08-10 2017-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 188,859 -13,589 -6.71 18,206 -2.36 0.0091
2017-05-05 2017-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 202,448 6,840 3.50 18,647 16.36 0.0096
2017-02-03 2016-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 195,608 -22,227 -10.20 16,025 -9.17 0.0088
2016-11-08 2016-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 217,835 -65,741 -23.18 17,643 -8.93 0.0099
2016-08-08 2016-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 283,576 19,692 7.46 19,374 15.36 0.0114
2016-05-12 2016-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 263,884 -4,619 -1.72 16,794 -1.83 0.0100
2016-02-11 2015-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 268,503 33,978 14.49 17,107 42.46 0.0100
2015-11-12 2015-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 234,525 -36,820 -13.57 12,008 -12.73 0.0074
2015-08-13 2015-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 271,345 -5,047 -1.83 13,760 -5.45 0.0078
2015-05-14 2015-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 276,392 -145,976 -34.56 14,553 -30.73 0.0084
2015-02-13 2014-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 422,368 263,793 166.35 21,009 200.77 0.0122
2014-11-14 2014-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 158,575 -104,415 -39.70 6,985 -37.28 0.0042
2014-08-13 2014-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 262,990 38,922 17.37 11,137 28.20 0.0066
2014-05-14 2014-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 224,068 4,490 2.04 8,687 14.14 0.0052
2014-02-14 2013-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 219,578 36,483 19.93 7,611 37.31 0.0046
2013-11-14 2013-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 183,095 -139,430 -43.23 5,543 -28.72 0.0036
2013-08-14 2013-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 322,525 322,525 7,776 0.0054
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.