Monolithic Power Systems, Inc.
MX ˙ BMV ˙ US6098391054
SecurityMX:MPWR / Monolithic Power Systems, Inc.
InstitutionQuadrant Capital Group Llc
Latest Disclosed Ownership1,411 shares
Latest Disclosed Value $ 1,542,717
Quadrant Capital Group Llc reports 0.49% decrease in ownership of MPWR / Monolithic Power Systems, Inc.

On May 13, 2026 - Quadrant Capital Group Llc filed a 13F-HR/A form disclosing ownership of 1,411 shares of Monolithic Power Systems, Inc. (MX:MPWR) valued at $1,542,717 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 1,418 shares of Monolithic Power Systems, Inc.. This represents a change in shares of -0.49% 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)
2026-05-13 2026-03-31 13F/A-1 MONOLITHIC PWR SYS COM 609839105 1,411 -7 -0.49 1,543 20.00 0.0461
2026-05-11 2026-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,411 -7 49 0.0369
2026-02-12 2025-12-31 13F MONOLITHIC PWR SYS COM 609839105 1,418 15 1.07 1,285 -0.46 0.0388
2025-11-13 2025-09-30 13F MONOLITHIC PWR SYS COM 609839105 1,403 5 0.36 1,292 26.32 0.0420
2025-08-13 2025-06-30 13F MONOLITHIC PWR SYS COM 609839105 1,398 347 33.02 1,022 67.82 0.0368
2025-05-13 2025-03-31 13F MONOLITHIC PWR SYS COM 609839105 1,051 591 128.48 610 123.90 0.0226
2025-02-13 2024-12-31 13F MONOLITHIC PWR SYS COM 609839105 460 -47 -9.27 272 -41.88 0.0187
2024-11-12 2024-09-30 13F MONOLITHIC PWR SYS COM 609839105 507 26 5.41 469 18.48 0.0326
2024-08-12 2024-06-30 13F MONOLITHIC PWR SYS COM 609839105 481 19 4.11 395 26.60 0.0293
2024-05-15 2024-03-31 13F MONOLITHIC PWR SYS COM 609839105 462 -1 -0.22 313 6.85 0.0247
2024-02-08 2023-12-31 13F MONOLITHIC PWR SYS COM 609839105 463 19 4.28 292 42.44 0.0251
2023-11-14 2023-09-30 13F MONOLITHIC PWR SYS COM 609839105 444 -7 -1.55 205 -15.64 0.0205
2023-08-10 2023-06-30 13F MONOLITHIC PWR SYS COM 609839105 451 24 5.62 244 14.08 0.0242
2023-05-11 2023-03-31 13F MONOLITHIC PWR SYS COM 609839105 427 -28 -6.15 214 33.13 0.0223
2023-02-13 2022-12-31 13F MONOLITHIC PWR SYS COM 609839105 455 -128 -21.96 161 -24.53 0.0182
2022-11-10 2022-09-30 13F MONOLITHIC PWR SYS COM 609839105 583 46 8.57 212 2.91 0.0280
2022-08-09 2022-06-30 13F MONOLITHIC PWR SYS COM 609839105 537 -68 -11.24 206 -29.93 0.0277
2022-05-06 2022-03-31 13F MONOLITHIC PWR SYS COM 609839105 605 152 33.55 294 31.84 0.0356
2022-02-01 2021-12-31 13F MONOLITHIC PWR SYS COM 609839105 453 24 5.59 223 7.21 0.0266
2021-11-12 2021-09-30 13F MONOLITHIC PWR SYS COM 609839105 429 13 3.12 208 34.19 0.0290
2021-08-09 2021-06-30 13F MONOLITHIC PWR SYS COM 609839105 416 -42 -9.17 155 -4.32 0.0225
2021-05-12 2021-03-31 13F MONOLITHIC PWR SYS COM 609839105 458 79 20.84 162 16.55 0.0263
2021-02-16 2020-12-31 13F MONOLITHIC PWR SYS COM 609839105 379 7 1.88 139 33.65 0.0258
2020-11-13 2020-09-30 13F MONOLITHIC PWR SYS COM 609839105 372 -600 -61.73 104 -54.78 0.0227
2020-08-13 2020-06-30 13F MONOLITHIC PWR SYS COM 609839105 972 628 182.56 230 277.05 0.0509
2020-05-15 2020-03-31 13F Monolithic Power Systems Com 609839105 344 36 11.69 61 27.08 0.0102
2020-03-19 2019-12-31 13F/A-1 Monolithic Power Systems Com 609839105 308 16 5.48 48 17.07 0.0058
2020-02-03 2019-12-31 13F Monolithic Power Systems Com 609839105 308 16 48 162.1983
2019-10-24 2019-09-30 13F Monolithic Power Systems COM 609839105 292 0 0.00 41 13.89 0.0063
2019-07-24 2019-06-30 13F Monolithic Power Systems COM 609839105 292 -380 -56.55 36 -58.14 0.0057
2019-04-29 2019-03-31 13F Monolithic Power Systems COM 609839105 672 333 98.23 86 152.94 0.0151
2019-01-17 2018-12-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 339 41 13.76 34 13.33 0.0091
2018-10-29 2018-09-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 298 0 0.00 30 -16.67 0.0086
2018-08-08 2018-06-30 13F MONOLITHIC POWER SYSTEMS COM 609839105 298 -81 -21.37 36 -5.26 0.0126
2018-05-10 2018-03-31 13F MONOLITHIC POWER SYSTEMS COM 609839105 379 297 362.20 38 375.00 0.0138
2018-01-31 2017-12-31 13F Monolithic Power Systems COM 609839105 82 0 0.00 8 14.29 0.0032
2017-10-13 2017-09-30 13F Monolithic Power Systems COM 609839105 82 18 28.12 7 133.33 0.0029
2017-08-14 2017-06-30 13F Monolithic Power Systems COM 609839105 64 0 0.00 3 -25.00 0.0013
2017-04-10 2017-03-31 13F Monolithic Power Systems COM 609839105 64 39 156.00 4 300.00 0.0018
2017-01-11 2016-12-31 13F Monolithic Power Systems COM 609839105 25 -20 -44.44 1 -66.67 0.0005
2016-10-25 2016-09-30 13F Monolithic Power Systems COM 609839105 45 0 0.00 3 50.00 0.0020
2016-07-28 2016-06-30 13F Monolithic Power Systems COM 609839105 45 19 73.08 2 100.00 0.0014
2016-04-27 2016-03-31 13F Monolithic Power Systems COM 609839105 26 26 0.00 1 0.0006
2016-01-28 2015-12-31 13F Monolithic Power Systems COM 609839105 0 -1,040 -100.00 0 -100.00
2015-10-28 2015-09-30 13F Monolithic Power Systems COM 609839105 1,040 0 0.00 53 1.92 0.0366
2015-08-12 2015-06-30 13F Monolithic Power Systems COM 609839105 1,040 1,040 52 0.0331
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.