MARKETAXESS HOLDINGS INC

Report of Independent Registered Public Accounting Firm

To the Board of Directors and Stockholders of MarketAxess Holdings Inc.

Opinions on the Financial Statements and Internal Control over Financial Reporting

We have audited the accompanying consolidated statements of financial condition of MarketAxess Holdings Inc. and its subsidiaries (the “Company”) as of December 31, 2025 and 2024, and the related consolidated statements of operations, of comprehensive income, of changes in stockholders’ equity and of cash flows for each of the three years in the period ended December 31, 2025, including the related notes (collectively referred to as the “consolidated financial statements”). We also have audited the Company's internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the Committee of Sponsoring Organizations of the Treadway Commission (COSO).

In our opinion, the consolidated financial statements referred to above present fairly, in all material respects, the financial position of the Company as of December 31, 2025 and 2024, and the results of its operations and its cash flows for each of the three years in the period ended December 31, 2025 in conformity with accounting principles generally accepted in the United States of America. Also in our opinion, the Company maintained, in all material respects, effective internal control over financial reporting as of December 31, 2025, based on criteria established in Internal Control - Integrated Framework (2013) issued by the COSO.

Basis for Opinions

The Company's management is responsible for these consolidated financial statements, for maintaining effective internal control over financial reporting, and for its assessment of the effectiveness of internal control over financial reporting, included in the accompanying Management’s Report on Internal Control Over Financial Reporting. Our responsibility is to express opinions on the Company’s consolidated financial statements and on the Company's internal control over financial reporting based on our audits. We are a public accounting firm registered with the Public Company Accounting Oversight Board (United States) (PCAOB) and are required to be independent with respect to the Company in accordance with the U.S. federal securities laws and the applicable rules and regulations of the Securities and Exchange Commission and the PCAOB.

We conducted our audits in accordance with the standards of the PCAOB. Those standards require that we plan and perform the audits to obtain reasonable assurance about whether the consolidated financial statements are free of material misstatement, whether due to error or fraud, and whether effective internal control over financial reporting was maintained in all material respects.

Our audits of the consolidated financial statements included performing procedures to assess the risks of material misstatement of the consolidated financial statements, whether due to error or fraud, and performing procedures that respond to those risks. Such procedures included examining, on a test basis, evidence regarding the amounts and disclosures in the consolidated financial statements. Our audits also included evaluating the accounting principles used and significant estimates made by management, as well as evaluating the overall presentation of the consolidated financial statements. Our audit of internal control over financial reporting included obtaining an understanding of internal control over financial reporting, assessing the risk that a material weakness exists, and testing and evaluating the design and operating effectiveness of internal control based on the assessed risk. Our audits also included performing such other procedures as we considered necessary in the circumstances. We believe that our audits provide a reasonable basis for our opinions.

Definition and Limitations of Internal Control over Financial Reporting

A company’s internal control over financial reporting is a process designed to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles. A company’s internal control over financial reporting includes those policies and procedures that (i) pertain to the maintenance of records that, in reasonable detail, accurately and fairly reflect the transactions and dispositions of the assets of the company; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with generally accepted accounting principles, and that receipts and expenditures of the company are being made only in accordance with authorizations of management and directors of the company; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use, or disposition of the company’s assets that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate.

Critical Audit Matters

The critical audit matters communicated below are matters arising from the current period audit of the consolidated financial statements that were communicated or required to be communicated to the audit committee and that (i) relate to accounts or disclosures that are material to the consolidated financial statements and (ii) involved our especially challenging, subjective, or complex judgments. The communication of critical audit matters does not alter in any way our opinion on the consolidated financial statements, taken as a whole, and we are not, by communicating the critical audit matters below, providing separate opinions on the critical audit matters or on the accounts or disclosures to which they relate.

Revenue Recognition - Variable Transaction Fees related to Open Trading Commissions

As described in Note 2 to the consolidated financial statements, the Company’s variable transaction fees related to Open Trading commissions were $175.6 million for the year ended December 31, 2025. Variable transaction fees are recognized on a trade date basis, are generally calculated as a percentage of the notional dollar volume of bonds traded on the platforms, and vary based on the type, size, yield, and maturity of the bond traded, as well as individual client incentives. For Open Trading trades that the Company executes between and among institutional investor and broker-dealer clients on a matched principal basis by serving as counterparty to both the buyer and the seller, the Company earns its commission through the difference in price between the two trades.

The principal consideration for our determination that performing procedures relating to revenue recognition for variable transaction fees related to Open Trading commissions is a critical audit matter is a high degree of auditor effort in performing procedures related to this commission fee type.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to the revenue recognition process, including controls over the calculation of variable transaction fees related to Open Trading commissions and the underlying data. These procedures also included, among others, testing a sample of variable transaction fees related to Open Trading commissions by (i) obtaining and inspecting source documents for both the buyer and seller trades, such as trade ticket, customer agreements, and evidence of settlement and (ii) recalculating the variable transaction fees related to Open Trading commission based on the difference in price between the trades with both the buyer and seller.

Acquisition of RFQ-hub Holdings LLC - Valuation of Developed Technology and Customer Relationships

As described in Note 6 to the consolidated financial statements, on May 9, 2025, the Company completed its acquisition of a 90.3% controlling stake in RFQ-hub Holdings LLC (“RFQ-hub”) for the total purchase price of $82.3 million. Of the acquired intangible assets, $16.9 million of developed technology and $12.6 million of customer relationships were recorded at fair value. The acquired developed technology and customer relationships were valued using the relief-from-royalty method and multi-period excess earnings methods, respectively. Determining the fair value of the developed technology and customer relationships intangible assets required judgment and involved the use of significant estimates and assumptions, including assumptions related to discount rates, revenue growth rates, customer attrition rates, royalty rates, technological obsolescence, contributory asset charges and asset lives.

The principal considerations for our determination that performing procedures relating to the valuation of developed technology and customer relationships acquired in the acquisition of RFQ-hub is a critical audit matter are (i) the significant judgment by management when developing the fair value estimate of the developed technology and customer relationships acquired; (ii) a high degree of auditor judgment, subjectivity, and effort in performing procedures and evaluating management’s significant assumptions related to discount rates, revenue growth rates, royalty rates, technological obsolescence and asset lives for developed technology and discount rates, revenue growth rates, customer attrition rates, contributory asset charges and asset lives for customer relationships; and (iii) the audit effort involved the use of professionals with specialized skill and knowledge.

Addressing the matter involved performing procedures and evaluating audit evidence in connection with forming our overall opinion on the consolidated financial statements. These procedures included testing the effectiveness of controls relating to the acquisition accounting, including controls over management’s valuation of the developed technology and customer relationships acquired. These procedures also included, among others, (i) reading the purchase agreement; (ii) testing management’s process for developing the fair value estimate of the developed technology and customer relationships acquired; (iii) testing the completeness and accuracy of certain underlying data used in the relief-from-royalty and multi-period excess earnings methods; and (iv) evaluating the reasonableness of the significant assumption used by management related to revenue growth rates for developed technology and customer relationships. Evaluating management’s assumption related to the revenue growth rates involved considering the current and past performance of RFQ-hub, the consistency with external market and industry data and whether the assumption was consistent with evidence obtained in other areas of the audit. Professionals with specialized skill and knowledge were used to assist in evaluating (i) the appropriateness of the relief-from-royalty and multi-period excess earnings methods used by management and (ii) the reasonableness of (a) the discount rates, royalty rates, technological obsolescence and asset lives assumptions for developed technology and (b) the discount rates, customer attrition rates, contributory asset charges and asset lives assumptions for customer relationships.

/s/ PricewaterhouseCoopers LLP

New York, New York

February 24, 2026

We have served as the Company’s auditor since 2000.

CONSOLIDATED STATEMENTS OF FINANCIAL CONDITION