Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionAmalgamated Bank
Latest Disclosed Ownership10,766 shares
Latest Disclosed Value $ 11,771
Amalgamated Bank reports 0.45% decrease in ownership of MPWR / Monolithic Power Systems, Inc.

On May 8, 2026 - Amalgamated Bank filed a 13F-HR form disclosing ownership of 10,766 shares of Monolithic Power Systems, Inc. (MX:MPWR) valued at $11,771 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 10,815 shares of Monolithic Power Systems, Inc.. This represents a change in shares of -0.45% 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)
2026-05-08 2026-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,766 -49 -0.45 12 22.22 0.0901
2026-02-05 2025-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,815 361 3.45 10 0.00 0.0707
2025-10-29 2025-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,454 148 1.44 10 28.57 0.0688
2025-08-04 2025-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,306 133 1.31 8 40.00 0.0582
2025-04-25 2025-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,173 216 2.17 6 0.00 0.0505
2025-02-04 2024-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,957 -375 -3.63 6 -44.44 0.0484
2024-10-30 2024-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,332 3 0.03 10 12.50 0.0787
2024-08-12 2024-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,329 38 0.37 8 33.33 0.0723
2024-04-23 2024-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,291 -2,643 -20.43 7 -25.00 0.0596
2024-02-06 2023-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,934 -64 -0.49 8 33.33 0.0651
2023-11-08 2023-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,998 829 6.81 6 0.00 0.0511
2023-08-11 2023-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,169 -293 -2.35 7 0.00 0.0532
2023-05-02 2023-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,462 186 1.52 6 50.00 0.0532
2023-02-10 2022-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,276 80 0.66 4 -99.91 0.0387
2022-11-09 2022-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,196 -656 -5.10 4,432 -10.21 0.0428
2022-08-15 2022-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 12,852 -4,722 -26.87 4,936 -42.17 0.0460
2022-08-25 2022-03-31 13F/A-1 MONOLITHIC POWER SYSTEMS COM 609839105 17,574 406 2.36 8,535 0.78 0.0663
2022-06-30 2022-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 17,574 406 8,535 0.0678
2022-02-15 2021-12-31 13F/A-1 MONOLITHIC POWER SYSTEMS COM 609839105 17,168 1,325 8.36 8,469 10.29 0.0625
2022-02-15 2021-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 17,168 1,325 8,469 0.0625
2021-10-29 2021-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 15,843 -462 -2.83 7,679 26.11 0.0648
2021-08-16 2021-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 16,305 7,627 87.89 6,089 98.66 0.0488
2021-05-13 2021-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 8,678 -498 -5.43 3,065 -8.81 0.1149
2021-02-12 2020-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,176 36 0.39 3,361 31.49 0.1274
2020-10-30 2020-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,140 -253 -2.69 2,556 14.82 0.1111
2020-08-10 2020-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,393 -2,014 -17.66 2,226 16.54 0.1030
2020-05-13 2020-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 11,407 -148 -1.28 1,910 -7.15 0.0467
2020-02-13 2019-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 11,555 609 5.56 2,057 20.72 0.0379
2019-11-13 2019-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 10,946 1,342 13.97 1,704 30.67 0.0358
2019-08-14 2019-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,604 -41 -0.43 1,304 -0.23 0.0304
2019-05-15 2019-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,645 137 1.44 1,307 18.28 0.0317
2019-02-15 2018-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,508 3,523 58.86 1,105 47.14 0.0313
2018-11-14 2018-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,985 -3,917 -39.56 751 -43.28 0.0186
2018-07-18 2018-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 9,902 4,175 72.90 1,324 99.70 0.0324
2018-05-22 2018-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,727 -93 -1.60 663 1.38 0.0176
2018-02-13 2017-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,820 345 6.30 654 12.18 0.0177
2017-11-09 2017-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,475 -242 -4.23 583 5.81 0.0182
2017-08-10 2017-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,717 387 7.26 551 12.22 0.0181
2017-05-12 2017-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,330 -12 -0.22 491 12.10 0.0244
2017-02-14 2016-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 5,342 671 14.37 438 16.49 0.0198
2016-11-15 2016-09-30 13F/A-1 MONOLITHIC POWER SYSTEMS COM 609839105 4,671 191 4.26 376 14.29 0.0218
2016-08-16 2016-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 4,480 317 7.61 329 24.15 0.0190
2016-05-11 2016-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 4,163 362 9.52 265 9.50 0.0258
2016-02-10 2015-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 3,801 -345 -8.32 242 14.15 0.0299
2015-11-04 2015-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 4,146 57 1.39 212 2.42 0.0222
2015-07-10 2015-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 4,089 170 4.34 207 0.49 0.0203
2015-04-22 2015-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 3,919 3,919 206 0.0251
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.