Note 1 - Basis of Presentation	3 Months Ended
Mar. 31, 2024
Notes to Financial Statements
Significant Accounting Policies [Text Block]	1. BASIS OF PRESENTATION The accompanying unaudited condensed consolidated financial statements have been prepared by Monolithic Power Systems, Inc. (the “Company” or “MPS”) in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in accordance with these accounting principles, rules and regulations. The information in this report should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 29, 2024. In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position, results of operations and cash flows for the interim periods presented. The financial statements contained in this Quarterly Report on Form 10-Q are not necessarily indicative of the results that may be expected for the year ending December 31, 2024 or for any other future periods. Summary of Significant Accounting Policies There have been no changes to the Company’s significant accounting policies during the three months ended March 31, 2024. In addition to those described in the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2023, the Company is subject to the following significant accounting policy due to the recent acquisition. Goodwill and Acquisition-Related Intangible Assets Goodwill represents the excess of fair value of purchase consideration over fair value of net tangible and identifiable intangible assets acquired as of the date of an acquisition. In-process research and development (“IPR&D”) assets represent the fair value of incomplete research and development (“R&D”) projects that had not reached technological feasibility as of the date of acquisition. IPR&D assets are initially capitalized at fair value as intangible assets with indefinite lives. When IPR&D projects are completed, they are reclassified as amortizable intangible assets and are amortized over their estimated useful lives. Alternatively, if IPR&D projects are abandoned, they are impaired and expensed as R&D costs. Acquisition-related intangible assets with finite lives consist of developed technologies, which are amortized on a straight-line basis over their estimated remaining useful lives. The amortization expense is recorded in cost of revenue in the Condensed Consolidated Statements of Operations. *Use of Estimates* The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions used in these condensed consolidated financial statements primarily include those related to revenue recognition, inventory valuation, valuation of share-based awards, contingencies and income tax valuation allowances. Actual results could differ from these estimates and assumptions, and any such differences may be material to the Company’s condensed consolidated financial statements. New Accounting Pronouncements Not Yet Adopted as of March 31, 2024 In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which aims to improve disclosures regarding a public entity’s reportable segments, primarily through more comprehensive disclosures around significant segment expenses. The standard is effective for annual periods beginning January 1, 2024 and for interim periods beginning January 1, 2025, and should be applied retroactively to all prior periods presented. The Company is evaluating the potential effect that the updated standard will have on its financial statement disclosures. In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which aims to improve an entity’s income tax disclosures around its effective rate reconciliation, income taxes paid, disaggregation of income before income taxes and income tax expense. The guidance will be effective for annual periods beginning January 1, 2025. The standard should be applied prospectively but retrospective application is permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements.

Note 1 - Basis of Presentation

3 Months Ended

Mar. 31, 2024

Significant Accounting Policies [Text Block]

1. BASIS OF PRESENTATION

The accompanying unaudited condensed consolidated financial statements have been prepared by Monolithic Power Systems, Inc. (the “Company” or “MPS”) in accordance with the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (“GAAP”) have been condensed or omitted in accordance with these accounting principles, rules and regulations. The information in this report should be read in conjunction with the Company’s audited consolidated financial statements and notes thereto included in the Annual Report on Form 10-K for the year ended December 31, 2023, filed with the SEC on February 29, 2024.

In the opinion of management, the accompanying unaudited condensed consolidated financial statements reflect all adjustments (consisting only of normal recurring adjustments) necessary to present fairly the Company’s financial position, results of operations and cash flows for the interim periods presented. The financial statements contained in this Quarterly Report on Form 10-Q are not necessarily indicative of the results that may be expected for the year ending December 31, 2024 or for any other future periods.

Summary of Significant Accounting Policies

There have been no changes to the Company’s significant accounting policies during the three months ended March 31, 2024. In addition to those described in the Company’s audited consolidated financial statements included in the Annual Report on Form 10-K for the year ended December 31, 2023, the Company is subject to the following significant accounting policy due to the recent acquisition.

Goodwill and Acquisition-Related Intangible Assets

Goodwill represents the excess of fair value of purchase consideration over fair value of net tangible and identifiable intangible assets acquired as of the date of an acquisition. In-process research and development (“IPR&D”) assets represent the fair value of incomplete research and development (“R&D”) projects that had not reached technological feasibility as of the date of acquisition. IPR&D assets are initially capitalized at fair value as intangible assets with indefinite lives. When IPR&D projects are completed, they are reclassified as amortizable intangible assets and are amortized over their estimated useful lives. Alternatively, if IPR&D projects are abandoned, they are impaired and expensed as R&D costs. Acquisition-related intangible assets with finite lives consist of developed technologies, which are amortized on a straight-line basis over their estimated remaining useful lives. The amortization expense is recorded in cost of revenue in the Condensed Consolidated Statements of Operations.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions used in these condensed consolidated financial statements primarily include those related to revenue recognition, inventory valuation, valuation of share-based awards, contingencies and income tax valuation allowances. Actual results could differ from these estimates and assumptions, and any such differences may be material to the Company’s condensed consolidated financial statements.

New Accounting Pronouncements Not Yet Adopted as of March 31, 2024

In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures, which aims to improve disclosures regarding a public entity’s reportable segments, primarily through more comprehensive disclosures around significant segment expenses. The standard is effective for annual periods beginning January 1, 2024 and for interim periods beginning January 1, 2025, and should be applied retroactively to all prior periods presented. The Company is evaluating the potential effect that the updated standard will have on its financial statement disclosures.

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which aims to improve an entity’s income tax disclosures around its effective rate reconciliation, income taxes paid, disaggregation of income before income taxes and income tax expense. The guidance will be effective for annual periods beginning January 1, 2025. The standard should be applied prospectively but retrospective application is permitted. The Company does not expect the adoption of this standard to have a material impact on its consolidated financial statements.