Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionState Street Corp
Latest Disclosed Ownership2,188,454 shares
Latest Disclosed Value $ 2,397,061,793
State Street Corp reports 0.37% increase in ownership of MPWR / Monolithic Power Systems, Inc.

On May 15, 2026 - State Street Corp filed a 13F-HR form disclosing ownership of 2,188,454 shares of Monolithic Power Systems, Inc. (MX:MPWR) valued at $2,397,061,793 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 2,180,419 shares of Monolithic Power Systems, Inc.. This represents a change in shares of 0.37% 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 PWR SYS COM 609839105 2,188,454 8,035 0.37 2,397,062 21.09 0.0828
2026-02-13 2025-12-31 13F MONOLITHIC PWR SYS COM 609839105 2,180,419 45,715 2.14 1,979,610 0.56 0.0664
2025-11-14 2025-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,134,704 14,670 0.69 1,968,578 26.69 0.0683
2025-08-14 2025-06-30 13F MONOLITHIC PWR SYS COM 609839105 2,120,034 4,329 0.20 1,553,828 26.30 0.0582
2025-05-15 2025-03-31 13F MONOLITHIC PWR SYS COM 609839105 2,115,705 -44,314 -2.05 1,230,300 -3.96 0.0507
2025-02-14 2024-12-31 13F MONOLITHIC PWR SYS COM 609839105 2,160,019 74,873 3.59 1,281,016 -33.64 0.0505
2024-11-14 2024-09-30 13F MONOLITHIC PWR SYS COM 609839105 2,085,146 42,678 2.09 1,930,301 14.85 0.0785
2024-08-14 2024-06-30 13F MONOLITHIC PWR SYS COM 609839105 2,042,468 47,877 2.40 1,680,773 24.17 0.0734
2024-05-15 2024-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,994,591 43,900 2.25 1,353,643 9.84 0.0605
2024-02-14 2023-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,950,691 70,100 3.73 1,232,390 41.54 0.0599
2023-11-14 2023-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,880,591 27,416 1.48 870,697 -13.19 0.0483
2023-08-14 2023-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,853,175 41,208 2.27 1,002,974 10.37 0.0527
2023-05-15 2023-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,811,967 53,355 3.03 908,748 45.83 0.0513
2023-05-15 2022-12-31 13F/A-99 MONOLITHIC PWR SYS COM 609839105 1,758,612 -28,607 -1.60 623,174 -4.24 0.0366
2023-05-15 2022-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,758,612 -28,607 623,174 0.0366
2022-11-15 2022-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,787,219 40,022 2.29 650,797 -3.20 0.0412
2022-08-15 2022-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,747,197 -69,292 -3.81 672,283 -23.91 0.0403
2022-05-16 2022-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,816,489 552 0.03 883,565 -1.49 0.0437
2022-02-14 2021-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,815,937 73,538 4.22 896,931 6.08 0.0425
2021-11-15 2021-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,742,399 12,615 0.73 845,545 30.68 0.0447
2021-08-16 2021-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,729,784 43,923 2.61 647,011 8.47 0.0341
2021-07-09 2021-03-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 1,685,861 278,332 19.77 596,467 15.55 0.0342
2021-05-17 2021-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,685,861 278,332 596,467 0.0342
2021-02-16 2020-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,407,529 366,676 35.23 516,178 77.05 0.0316
2020-11-10 2020-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,040,853 -59,862 -5.44 291,550 11.53 0.0199
2020-08-14 2020-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,100,715 33,231 3.11 261,421 45.81 0.0190
2020-06-19 2020-03-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 1,067,484 12,863 1.22 179,291 -4.72 0.0157
2020-05-11 2020-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,067,484 12,863 179,291 15,745.3599
2020-02-06 2019-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,054,621 3,433 0.33 188,171 14.73 0.0129
2019-11-14 2019-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,051,188 -1,265 -0.12 164,014 14.44 0.0122
2019-08-14 2019-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,052,453 -6,494 -0.61 143,318 -0.40 0.0107
2019-05-15 2019-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,058,947 56,416 5.63 143,897 23.16 0.0112
2019-02-12 2018-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,002,531 -87,649 -8.04 116,842 -14.62 0.0106
2018-11-09 2018-09-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,090,180 15,518 1.44 136,852 -4.73 0.0105
2018-08-14 2018-06-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,074,662 -311,193 -22.45 143,648 -10.46 0.0120
2018-05-15 2018-03-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,385,855 -17,811 -1.27 160,436 1.72 0.0136
2018-02-14 2017-12-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,403,666 21,689 1.57 157,719 7.11 0.0127
2017-11-14 2017-09-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,381,977 19,416 1.42 147,251 12.10 0.0127
2017-08-14 2017-06-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,362,561 48,013 3.65 131,351 8.50 0.0116
2017-05-15 2017-03-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,314,548 52,796 4.18 121,061 17.11 0.0108
2017-02-09 2016-12-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,261,752 -9,660 -0.76 103,374 1.00 0.0097
2017-01-13 2016-09-30 13F/A-1 MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,271,412 423,975 50.03 102,350 76.80 0.0103
2016-11-14 2016-09-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 1,271,412 102,350
2016-08-12 2016-06-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 847,437 -655 -0.08 57,890 7.27 0.0062
2016-05-20 2016-03-31 13F/A-1 MONOLITHIC POWER SYSTEMS Common equity shares 609839105 848,092 11,822 1.41 53,969 1.30 0.0058
2016-05-12 2016-03-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 848,092 53,969
2016-02-16 2015-12-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 836,270 41,729 5.25 53,276 30.97 0.0058
2015-11-16 2015-09-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 794,541 -43,172 -5.15 40,677 -4.25 0.0047
2015-08-13 2015-06-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 837,713 41,017 5.15 42,484 1.29 0.0045
2015-05-15 2015-03-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 796,696 8,826 1.12 41,944 7.03 0.0043
2015-02-11 2014-12-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 787,870 7,819 1.00 39,189 14.06 0.0039
2014-11-12 2014-09-30 13F/A-1 MONOLITHIC POWER SYSTEMS Common equity shares 609839105 780,051 -8,223 -1.04 34,358 2.92 0.0037
2014-11-10 2014-09-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 780,051 34,358
2014-08-12 2014-06-30 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 788,274 20,323 2.65 33,384 12.12 0.0036
2014-05-15 2014-03-31 13F/A-1 MONOLITHIC POWER SYSTEMS Common equity shares 609839105 767,951 -8,467 -1.09 29,774 10.64 0.0034
2014-05-13 2014-03-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 767,951 29,774
2014-02-06 2013-12-31 13F/A-1 MONOLITHIC POWER SYSTEMS Common equity shares 609839105 776,418 70,468 9.98 26,911 25.92 0.0030
2014-02-06 2013-12-31 13F MONOLITHIC POWER SYSTEMS Common equity shares 609839105 635,332 14,159
2013-11-12 2013-09-30 13F MONOLITHIC POWER SYSTEMS Common Stock 609839105 705,950 36,454 5.44 21,371 32.40 0.0026
2013-08-08 2013-06-30 13F MONOLITHIC POWER SYSTEMS Common Stock 609839105 669,496 669,496 16,141 0.0021
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.