Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionBlackRock, Inc.
Latest Disclosed Ownership4,899,383 shares
Ownership 10.20%
BlackRock, Inc. ownership in MPWR / Monolithic Power Systems, Inc.

2026-01-08 - BlackRock, Inc. has filed an SCHEDULE 13G/A form with the Securities and Exchange Commission (SEC) disclosing ownership of 4,899,383 shares of Monolithic Power Systems, Inc. (MX:MPWR). This represents 10.2 percent ownership of the company. In their previous filing dated 2025-04-17 , BlackRock, Inc. had reported owning 4,674,772 shares, indicating an increase of 4.80 percent.

Institutional Ownership: 13D/G Filings

This table shows a history of the 13D/G filings made by the investor and/or investor group. Note that the share values in this table are not directly comparable to any numbers shown in the 13F table (if any).

File
Date		Effective
Date		Form Prev
Shares		 Latest
Shares		 ΔShares
(Percent)		 Ownership
(Percent)		 ΔOwnership
(Percent)
2026-01-08 2026-01-08 13G/A 4,674,772 4,899,383 4.80 10.20 4.08
2025-04-17 2025-04-17 13G/A 5,236,453 4,674,772 -10.73 9.80 -10.09
2025-04-17 2025-04-17 13G/A 5,236,453 4,674,772 -10.73 9.80 -10.09
2024-01-24 2024-01-24 13G/A 5,455,114 5,236,453 -4.01 10.90 -6.03
2023-01-26 2023-01-26 13G/A 5,455,114 5,455,114 0.00 11.60 0.00
2023-01-20 2023-01-20 13G 5,979,931 5,455,114 -8.78 11.60 -10.77
2022-01-28 2022-01-28 13G/A 6,314,697 5,979,931 -5.30 13.00 -7.14
2021-01-26 2021-01-26 13G/A 4,585,196 6,314,697 37.72 14.00 32.08
2020-02-04 2020-02-04 13G/A 4,374,908 4,585,196 4.81 10.60 3.92
2019-06-07 2019-06-07 13G/A 4,168,792 4,374,908 4.94 10.20 4.08
2019-02-06 2019-02-06 13G/A 4,204,988 4,168,792 -0.86 9.80 -2.97
2018-01-19 2018-01-19 13G/A 4,194,771 4,204,988 0.24 10.10 -1.94
2017-02-08 2017-02-08 13G/A 3,983,864 4,194,771 5.29 10.30 5.10
2017-01-25 2017-01-25 13G/A 3,554,887 3,983,864 12.07 9.80 8.89
2016-01-26 2016-01-26 13G/A 3,554,887 9.00
2015-01-23 2015-01-23 13G/A 3,163,724 8.20
2014-01-30 2014-01-30 13G/A 3,053,043 8.00
2013-02-05 2013-02-05 13G/A 2,296,058 6.47
2012-02-13 2012-02-13 13G/A 2,279,430 6.77

Important Note: One of the primary uses of the 13D/G filings is to evaluate the ability of a firm to control a company (ie, the "beneficial ownership"). To that end, firms are required to report not just direct holdings in companies, but indirect holdings that they control. For investment firms, these indirect holdings can include shares in funds they manage, advisory accounts, and in the case of activist campaigns, pledged votes. Therefore, share counts listed in 13D/G filings can differ significantly than share counts listed in 13F filings.

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)
2026-05-13 2026-03-31 13F MONOLITHIC PWR SYS COM 609839105 6,072,467 110,076 1.85 6,639,332 22.86 0.1160
2026-02-12 2025-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,962,391 235,617 4.11 5,404,073 2.50 0.0913
2025-11-12 2025-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,726,774 497,553 9.51 5,272,298 37.85 0.0923
2025-08-12 2025-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,229,221 316,313 6.44 3,824,548 34.22 0.0728
2025-05-02 2025-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,912,908 -509,319 -9.39 2,849,388 -11.19 0.0598
2025-02-07 2024-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,422,227 -381,736 -6.58 3,208,332 -40.21 0.0649
2024-11-13 2024-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,803,963 -103,386 -1.75 5,365,764 10.54 0.1126
2024-08-13 2024-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,907,349 542,434 10.11 4,853,950 33.56 0.1099
2024-05-10 2024-03-31 13F MONOLITHIC PWR SYS COM 609839105 5,364,915 128,385 2.45 3,634,301 10.03 0.0846
2024-02-13 2023-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,236,530 -43,274 -0.82 3,303,098 35.41 0.0842
2023-11-13 2023-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,279,804 -151,650 -2.79 2,439,269 -16.87 0.0701
2023-08-11 2023-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,431,454 257,328 4.97 2,934,234 13.30 0.0809
2023-05-12 2023-03-31 13F MONOLITHIC PWR SYS COM 609839105 5,174,126 -281,074 -5.15 2,589,857 34.26 0.0764
2023-02-13 2022-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,455,200 72,562 1.35 1,929,013 -1.38 0.0604
2022-11-14 2022-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,382,638 -381,988 -6.63 1,956,050 -11.64 0.0665
2022-08-12 2022-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,764,626 -484,856 -7.76 2,213,847 -27.06 0.0710
2022-05-12 2022-03-31 13F MONOLITHIC PWR SYS COM 609839105 6,249,482 269,551 4.51 3,035,249 2.89 0.0818
2022-02-10 2021-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,979,931 49,738 0.84 2,950,081 2.64 0.0751
2021-11-09 2021-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,930,193 55,039 0.94 2,874,245 31.00 0.0805
2021-08-11 2021-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,875,154 319,483 5.75 2,194,077 11.81 0.0611
2021-05-07 2021-03-31 13F MONOLITHIC PWR SYS COM 609839105 5,555,671 -759,026 -12.02 1,962,316 -15.15 0.0577
2021-02-05 2020-12-31 13F MONOLITHIC PWR SYS COM 609839105 6,314,697 737,757 13.23 2,312,630 48.31 0.0738
2020-11-06 2020-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,576,940 302,370 5.73 1,559,369 24.74 0.0575
2020-08-14 2020-06-30 13F MONOLITHIC PWR SYS COM 609839105 5,274,570 612,428 13.14 1,250,073 60.12 0.0499
2020-05-01 2020-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,662,142 76,946 1.68 780,724 -4.35 0.0382
2020-02-13 2019-12-31 13F MONOLITHIC PWR SYS COM 609839105 4,585,196 131,277 2.95 816,257 17.76 0.0313
2019-11-08 2019-09-30 13F MONOLITHIC PWR SYS COM 609839105 4,453,919 47,038 1.07 693,163 15.84 0.0291
2019-08-22 2019-06-30 13F/A-1 MONOLITHIC PWR SYS COM 609839105 4,406,881 168,988 3.99 598,366 4.21 0.0256
2019-08-13 2019-06-30 13F MONOLITHIC PWR SYS COM 609839105 4,406,881 168,988 598,366
2019-05-09 2019-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,237,893 69,101 1.66 574,193 18.48 0.0256
2019-02-08 2018-12-31 13F MONOLITHIC PWR SYS COM 609839105 4,168,792 -29,470 -0.70 484,622 -8.04 0.0245
2018-11-09 2018-09-30 13F MONOLITHIC PWR SYS COM 609839105 4,198,262 408,839 10.79 527,006 4.04 0.0228
2018-08-09 2018-06-30 13F MONOLITHIC PWR SYS COM 609839105 3,789,423 -868,251 -18.64 506,531 -6.06 0.0233
2018-05-09 2018-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,657,674 452,686 10.77 539,220 14.13 0.0258
2018-02-09 2017-12-31 13F MONOLITHIC PWR SYS COM 609839105 4,204,988 -5,983 -0.14 472,472 5.30 0.0225
2017-11-14 2017-09-30 13F MONOLITHIC PWR SYS COM 609839105 4,210,971 175,170 4.34 448,677 15.33 0.0226
2017-08-10 2017-06-30 13F MONOLITHIC PWR SYS COM 609839105 4,035,801 -150,854 -3.60 389,051 0.90 0.0206
2017-05-12 2017-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,186,655 4,170,068 25,140.58 385,591 28,273.14 0.0212
2017-02-10 2016-12-31 13F MONOLITHIC PWR SYS COM 609839105 16,587 -417 -2.45 1,359 -0.73 0.0019
2016-11-08 2016-09-30 13F MONOLITHIC PWR SYS COM 609839105 17,004 13,279 356.48 1,369 438.98 0.0020
2016-08-10 2016-06-30 13F MONOLITHIC PWR SYS COM 609839105 3,725 1,156 45.00 254 54.88 0.0004
2016-05-10 2016-03-31 13F MONOLITHIC PWR SYS COM 609839105 2,569 501 24.23 164 24.24 0.0003
2016-02-11 2015-12-31 13F MONOLITHIC PWR SYS COM 609839105 2,068 139 7.21 132 34.69 0.0002
2015-11-13 2015-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,929 -1,416 -42.33 98 -42.35 0.0002
2015-08-07 2015-06-30 13F MONOLITHIC PWR SYS COM 609839105 3,345 -1,289 -27.82 170 -30.33 0.0003
2015-05-13 2015-03-31 13F MONOLITHIC PWR SYS COM 609839105 4,634 3,468 297.43 244 320.69 0.0003
2015-02-09 2014-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,166 -222 -15.99 58 -4.92 0.0001
2014-10-29 2014-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,388 222 19.04 61 24.49 0.0001
2014-08-06 2014-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,166 -2 -0.17 49 8.89 0.0001
2014-05-02 2014-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,168 0 0.00 45 9.76 0.0001
2014-02-12 2013-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,168 -101 -7.96 41 5.13 0.0001
2013-11-12 2013-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,269 139 12.30 39 44.44 0.0001
2013-08-13 2013-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,130 1,130 27 0.0001
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.