Monolithic Power Systems, Inc.
US ˙ NasdaqGS ˙ US6098391054

SecurityMPWR / Monolithic Power Systems, Inc.
InstitutionLegal & General Group Plc
Latest Disclosed Ownership380,089 shares
Latest Disclosed Value $ 415,570,309
Legal & General Group Plc reports 6.58% increase in ownership of MPWR / Monolithic Power Systems, Inc.

On May 8, 2026 - Legal & General Group Plc filed a 13F-HR form disclosing ownership of 380,089 shares of Monolithic Power Systems, Inc. (US:MPWR) valued at $415,570,308 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 9, 2026 disclosing 356,639 shares of Monolithic Power Systems, Inc.. This represents a change in shares of 6.58% during the quarter. The current value of the position is $562,930,813 USD.

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.

Upgrade to unlock premium data and export to Excel .

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 PWR SYS COM 609839105 380,089 23,450 6.58 415,570 28.56 0.0961
2026-02-09 2025-12-31 13F MONOLITHIC PWR SYS COM 609839105 356,639 -1,790 -0.50 323,243 -2.04 0.0717
2025-11-13 2025-09-30 13F MONOLITHIC PWR SYS COM 609839105 358,429 7,855 2.24 329,984 28.70 0.0740
2025-08-12 2025-06-30 13F MONOLITHIC PWR SYS COM 609839105 350,574 13,841 4.11 256,403 31.29 0.0636
2025-05-15 2025-03-31 13F MONOLITHIC PWR SYS COM 609839105 336,733 9,555 2.92 195,298 0.88 0.0532
2025-02-13 2024-12-31 13F MONOLITHIC PWR SYS COM 609839105 327,178 40,641 14.18 193,591 -26.92 0.0512
2025-02-28 2024-09-30 13F/A-2 MONOLITHIC PWR SYS COM 609839105 286,537 55,887 24.23 264,904 39.78 0.0697
2024-11-14 2024-09-30 13F/A-1 MONOLITHIC PWR SYS COM 609839105 389,702 92,559 360,280 0.0751
2024-11-14 2024-09-30 13F MONOLITHIC PWR SYS COM 609839105 389,702 92,559 360,280 0.0379
2025-05-29 2024-06-30 13F/A-1 MONOLITHIC PWR SYS COM 609839105 230,650 -24,824 -9.72 189,520 9.51 0.0535
2024-08-14 2024-06-30 13F MONOLITHIC PWR SYS COM 609839105 297,143 -24,492 244,156 0.0547
2025-05-29 2024-03-31 13F/A-2 MONOLITHIC PWR SYS COM 609839105 255,474 -1,131 -0.44 173,062 6.92 0.0498
2024-07-01 2024-03-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 321,635 1,049 217,881 0.0509
2024-05-14 2024-03-31 13F MONOLITHIC PWR SYS COM 609839105 318,626 -1,960 215,843 0.0260
2025-05-29 2023-12-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 256,605 -15,379 -5.65 161,862 28.81 0.0503
2024-02-15 2023-12-31 13F MONOLITHIC PWR SYS COM 609839105 320,586 48,602 202,220 0.0519
2023-11-14 2023-09-30 13F MONOLITHIC PWR SYS COM 609839105 271,984 -12,224 -4.30 125,657 -18.16 0.0438
2023-08-14 2023-06-30 13F MONOLITHIC PWR SYS COM 609839105 284,208 7,149 2.58 153,538 10.71 0.0499
2023-05-15 2023-03-31 13F MONOLITHIC PWR SYS COM 609839105 277,059 5,048 1.86 138,679 44.18 0.0496
2023-02-14 2022-12-31 13F MONOLITHIC PWR SYS COM 609839105 272,011 -27,834 -9.28 96,186 -11.73 0.0369
2022-11-14 2022-09-30 13F MONOLITHIC PWR SYS COM 609839105 299,845 -24,140 -7.45 108,964 -12.43 0.0426
2022-08-22 2022-06-30 13F MONOLITHIC PWR SYS COM 609839105 323,985 40,873 14.44 124,424 -9.51 0.0440
2022-05-16 2022-03-31 13F MONOLITHIC PWR SYS COM 609839105 283,112 3,076 1.10 137,501 -0.47 0.0418
2022-02-14 2021-12-31 13F MONOLITHIC PWR SYS COM 609839105 280,036 -9,222 -3.19 138,150 -1.46 0.0418
2021-11-15 2021-09-30 13F MONOLITHIC PWR SYS COM 609839105 289,258 -26 -0.01 140,198 29.77 0.0456
2021-08-12 2021-06-30 13F MONOLITHIC PWR SYS COM 609839105 289,284 16,366 6.00 108,033 12.07 0.0361
2021-05-17 2021-03-31 13F MONOLITHIC PWR SYS COM 609839105 272,918 77,111 39.38 96,397 34.42 0.0359
2021-02-12 2020-12-31 13F MONOLITHIC PWR SYS COM 609839105 195,807 106,837 120.08 71,711 188.26 0.0281
2020-11-13 2020-09-30 13F MONOLITHIC PWR SYS COM 609839105 88,970 5,294 6.33 24,877 25.45 0.0111
2020-08-14 2020-06-30 13F MONOLITHIC PWR SYS COM 609839105 83,676 4,386 5.53 19,831 49.35 0.0096
2020-05-14 2020-03-31 13F MONOLITHIC PWR SYS COM 609839105 79,290 2,656 3.47 13,278 -2.68 0.0078
2020-02-13 2019-12-31 13F MONOLITHIC PWR SYS COM 609839105 76,634 10,547 15.96 13,643 52.05 0.0065
2019-08-14 2019-06-30 13F MONOLITHIC PWR SYS COM 609839105 66,087 17,112 34.94 8,973 35.22 0.0048
2019-05-15 2019-03-31 13F MONOLITHIC PWR SYS COM 609839105 48,975 1,145 2.39 6,636 19.35 0.0038
2019-02-15 2018-12-31 13F MONOLITHIC PWR SYS COM 609839105 47,830 2,856 6.35 5,560 -1.51 0.0043
2018-11-20 2018-09-30 13F MONOLITHIC PWR SYS COM 609839105 44,974 832 1.88 5,645 -4.32 0.0040
2018-08-10 2018-06-30 13F MONOLITHIC PWR SYS COM 609839105 44,142 1,976 4.69 5,900 20.88 0.0046
2018-05-17 2018-03-31 13F MONOLITHIC PWR SYS COM 609839105 42,166 6,358 17.76 4,881 21.24 0.0037
2018-02-13 2017-12-31 13F MONOLITHIC PWR SYS COM 609839105 35,808 1,696 4.97 4,026 10.76 0.0029
2017-11-09 2017-09-30 13F MONOLITHIC PWR SYS COM 609839105 34,112 2,863 9.16 3,635 20.60 0.0027
2017-08-03 2017-06-30 13F MONOLITHIC PWR SYS COM 609839105 31,249 6,596 26.76 3,014 32.83 0.0024
2017-05-12 2017-03-31 13F MONOLITHIC PWR SYS COM 609839105 24,653 5,365 27.82 2,269 43.15 0.0019
2017-02-13 2016-12-31 13F MONOLITHIC PWR SYS COM 609839105 19,288 9,064 88.65 1,585 93.53 0.0015
2016-10-12 2016-09-30 13F MONOLITHIC PWR SYS COM 609839105 10,224 2,137 26.43 819 50.00 0.0008
2016-08-16 2016-06-30 13F MONOLITHIC PWR SYS COM 609839105 8,087 0 0.00 546 7.27 0.0006
2016-05-16 2016-03-31 13F MONOLITHIC PWR SYS COM 609839105 8,087 -240 -2.88 509 -4.14 0.0006
2016-02-16 2015-12-31 13F MONOLITHIC PWR SYS COM 609839105 8,327 698 9.15 531 37.56 0.0006
2015-11-13 2015-09-30 13F MONOLITHIC PWR SYS COM 609839105 7,629 363 5.00 386 4.32 0.0005
2015-07-31 2015-06-30 13F MONOLITHIC PWR SYS COM 609839105 7,266 683 10.38 370 6.02 0.0004
2015-05-14 2015-03-31 13F MONOLITHIC PWR SYS COM 609839105 6,583 975 17.39 349 24.20 0.0004
2015-02-20 2014-12-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 5,608 0 0.00 281 13.31 0.0003
2015-02-17 2014-12-31 13F MONOLITHIC PWR SYS COM 609839105 5,608 0 281 0.0003
2014-11-14 2014-09-30 13F MONOLITHIC PWR SYS COM 609839105 5,608 5,608 248 0.0003
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.