You should read the following discussion in conjunction with the condensed consolidated financial statements and notes thereto included elsewhere in this Quarterly Report on Form 10-Q and our Annual Report on Form 10-K for the year ended December 31, 2025. Overview Five9 is a leading provider of the Intelligent CX Platform for enterprise contact centers. With a foundation in our cloud-native solution, Five9 is now evolving into an AI-native CX platform, empowering enterprises to scale seamlessly, innovate faster, and deliver enhanced customer experiences as our market opportunity continues to expand. Our reliable, secure, and scalable Intelligent CX Platform, powered by our Five9 Genius AI suite, delivers a comprehensive suite of easy-to-use applications that enable the breadth of customer service, sales, and marketing functions. We have become an established leader in the AI-powered CX market with more than 3,000 customers. Our Genius AI suite is a comprehensive portfolio of AI solutions that uses Generative AI to power agentic CX. The contact center is the system of record for interactions with full conversation history, and our platform serves as a real-time orchestration engine for every customer interaction across all channels, whether it is with a human or AI agent. As a result, our platform is designed to deliver a seamless collaboration between human agents and AI agents, where each interaction strengthens the next. This continuous learning loop compounds over time, creating a powerful data flywheel that drives higher performance, accuracy, and personalization for every customer engagement. We believe this is the structural advantage of our end-to-end AI-powered CX platform. We provide our solution through a software-as-a-service, or SaaS, business model. We generate subscription revenue from our Intelligent CX Platform and also generate usage-based telephony revenue. We charge our customers monthly subscription fees for access to our Intelligent CX Platform, primarily based on the number of licenses, as well as on a consumption basis for our AI solutions. Our customers generally purchase both subscriptions and related telephony usage from us. However, a growing number of our customers subscribe to our platform but purchase telephony usage directly from wholesale telecommunications service providers. We offer monthly, annual and multiple-year contracts to our customers, generally with 30 days’ notice required for limited reductions in the number of licenses or the level of consumption. Increases in the number of licenses or the level of consumption can be provisioned almost immediately. Subscription fees are generally billed monthly in advance, while telecom fees are billed in arrears. For each of the three and six months ended June 30, 2026, subscription and telecom fees accounted for 94% of our revenue. For each of the three and six months ended June 30, 2025, subscription and telecom fees accounted for 93% of our revenue. The remainder was comprised of professional services revenue from the implementation and optimization of our solution. Macroeconomic Factors We are subject to risks and exposures, including new and continued macroeconomic challenges resulting from the impact of global tariff increases and potential future increases and announcements regarding same, as well as the impact of current and potential global conflicts. While the implications of macroeconomic challenges on our business, results of operations and overall financial position remain uncertain over the long term, we believe such macroeconomic challenges could have an adverse impact on our revenue in future periods. Restructurings On March 31, 2025, our Board of Directors approved a reduction in force plan, or the 2025 Plan, as part of our broader efforts to prioritize investments in key strategic areas, including artificial intelligence, as well as to drive profitable growth and support our positive, long-term outlook and increasing stockholder value. On April 3, 2025, we commenced execution of the 2025 Plan, which resulted in the reduction of our global full-time employees by approximately 4%. During the year ended December 31, 2025, we incurred a total of $7.9 million in cash restructuring costs under the 2025 Plan, primarily consisting of notice period payments, severance payments, employee benefits and related costs, all of which are cash expenditures, of which $1.6 million was recorded in cost of revenue, $1.9 million was recorded in research and development expenses, $3.4 million was recorded in sales and marketing expenses, and $1.0 million was recorded in general and administrative expenses on the consolidated statements of operations and comprehensive income (loss). During the year ended December 31, 2025, we also incurred an additional $2.1 million in stock-based compensation costs related to the 2025 Plan due to additional vesting of share-based awards, of which $0.3 million was recorded in cost of revenue, $0.5 million was recorded in research and development expenses, $1.1 million was recorded in sales and marketing expenses, and $0.2 million was recorded in general and administrative expenses on the consolidated statements of operations and comprehensive income (loss). We do not expect to incur any additional costs under the 2025 Plan. 31 Table of Contents On April 27, 2026, we initiated a plan to consolidate our corporate headquarters in San Ramon, California by reducing the facility space we occupy from two floors to a single floor in May 2026, or the HQ Plan. The HQ Plan resulted in excess facility space that we intend to sublease. During each of the three and six months ended June 30, 2026, we incurred a total of $8.4 million in impairment charge ($7.4 million related to operating lease right-of-use assets and $1.0 million related to property and equipment) under the HQ Plan, which was recorded in general and administrative expenses on the consolidated statements of operations and comprehensive income (loss). The impairment charge was estimated based on a review and analysis of real estate market conditions, our projected sublease income and sublease commencement assumptions. Key GAAP Operating Results Our revenue increased to $312.4 million and $617.8 million for the three and six months ended June 30, 2026 from $283.3 million and $563.0 million for the three and six months ended June 30, 2025. Revenue growth was primarily attributable to our larger customers, driven by an increase in our sales and marketing activities and our improved brand awareness. For each of the three and six months ended June 30, 2026 and 2025, no single customer accounted for more than 10% of our total revenue. As of June 30, 2026, we had over 3,000 customers across multiple industries with a wide range of license sizes. We had net income of $3.4 million and $21.8 million in the three and six months ended June 30, 2026, respectively, compared to net income of $1.2 million and $1.7 million in the three and six months ended June 30, 2025, respectively. We have continued to make significant expenditures and investments, including in sales and marketing, research and development, infrastructure and investments in complementary businesses, technologies and intellectual property rights. We primarily evaluate the success of our business based on revenue growth and the efficiency and effectiveness of our investments. The growth of our business and our future success depend on many factors, including our ability to continue to expand our base of larger customers, grow revenue from our existing customers, innovate and expand internationally. While these areas represent significant opportunities for us, they also pose risks and challenges that we must successfully address, including new and continued macroeconomic challenges resulting from the impact of global tariff increases and potential future increases and announcements regarding same, as well as the impact of current and potential global conflicts, in order to successfully grow our business and improve our operating results. Key Operating and Non-GAAP Financial Performance Metrics In addition to measures of financial performance presented in our condensed consolidated financial statements, we monitor the key metrics set forth below to help us evaluate growth trends, establish budgets, measure the effectiveness of our sales and marketing efforts and assess operational efficiencies. Annual Dollar-Based Retention Rate We believe that our Annual Dollar-Based Retention Rate provides insight into our ability to retain and grow revenue from our customers, and is a measure of the long-term value of our customer relationships. Our Annual Dollar-Based Retention Rate is calculated by dividing our Retained Net Revenue by our Retention Base Net Revenue on a monthly basis, which we then average using the rates for the trailing twelve months for the period presented. We define Retention Base Net Revenue in two ways. First is subscription plus telecom revenue from all customers in the comparable prior year period. Second is subscription revenue from all customers in the comparable prior year period. Similarly, we define Retained Net Revenue as either subscription plus telecom revenue or subscription revenue from that same group of customers in the current period. We consider both subscription and telecom to be recurring revenue. The following table shows our Annual Dollar-Based Retention Rate based on subscription plus telecom revenue as well as subscription revenue for the periods presented: Twelve Months Ended June 30, 2026 June 30, 2025 Annual Dollar-Based Retention Rate (Subscription plus Telecom Revenue) 106% 108% Annual Dollar-Based Retention Rate (Subscription Revenue) 107% 109% The year-over-year decrease for annual dollar-based retention rate for both subscription plus telecom revenue as well as subscription revenue reflects year-over-year challenges related to a single large new customer ramping 32 Table of Contents significantly throughout 2024 and seasonal increases being stronger in the second half of 2024, offset in part by ongoing momentum in AI and expansion of larger existing customers throughout 2025 and the first half of 2026. Adjusted EBITDA We monitor adjusted EBITDA, a non-GAAP financial measure, to analyze our financial results and believe that it is useful to investors, as a supplement to U.S. GAAP measures, in evaluating our ongoing operational performance and enhancing an overall understanding of our past financial performance. We believe that adjusted EBITDA helps illustrate underlying trends in our business that could otherwise be masked by the effect of the income or expenses that we exclude from adjusted EBITDA. Furthermore, we use this measure to establish budgets and operational goals for managing our business and evaluating our performance. We also believe that adjusted EBITDA provides an additional tool for investors to use in comparing our recurring core business operating results over multiple periods with other companies in our industry. Adjusted EBITDA should not be considered in isolation from, or as a substitute for, financial information prepared in accordance with U.S. GAAP, and our calculation of adjusted EBITDA may differ from that of other companies in our industry. We compensate for the inherent limitations associated with using adjusted EBITDA through disclosure of these limitations, presentation of our financial statements in accordance with U.S. GAAP and reconciliation of adjusted EBITDA to the most directly comparable U.S. GAAP measure, net income. We calculate adjusted EBITDA as net income before (1) depreciation and amortization, (2) stock-based compensation, (3) interest expense, (4) interest income and other, (5) acquisition and related transaction costs and one-time integration costs, (6) lease amortization for finance leases, (7) costs related to reduction in force plans, (8) one-time expenses related to strategic consulting services for operational review, (9) other cost-reduction and productivity initiatives, (10) one-time expenses related to advisory services for long-term strategy and growth, (11) legal fees related to the securities class action, (12) office closure lease termination costs, (13) impairment charge related to consolidation of corporate headquarters, (14) provision for income taxes, and (15) other items that do not directly affect what we consider to be our core operating performance. 33 Table of Contents The following table shows a reconciliation of net income to adjusted EBITDA for the periods presented (in thousands): Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 June 30, 2026 June 30, 2025 Net income $ 3,367 $ 1,154 $ 21,779 $ 1,730 Non-GAAP adjustments: Depreciation and amortization (1) 19,919 14,649 37,761 29,139 Stock-based compensation (2) 32,980 41,859 65,644 81,104 Interest expense 3,507 3,820 6,649 7,935 Interest income and other (5,838) (7,917) (11,050) (18,220) Acquisition and related transaction costs and one-time integration costs 1,794 1,489 3,476 2,470 Lease amortization for finance leases 2,225 2,311 4,507 4,319 Costs related to reduction in force plans — 7,766 — 7,766 One-time expenses related to strategic consulting services for operational review — — — 1,265 Other cost-reduction and productivity initiatives — 974 (3) 974 One-time expenses related to advisory services for long-term strategy and growth 1,921 — 3,096 — Legal fees related to the securities class action 854 368 1,201 509 Office closure lease termination costs — 95 — 95 Impairment charge related to consolidation of corporate headquarters 8,382 — 8,382 — Provision for income taxes 941 1,382 3,092 1,566 Adjusted EBITDA $ 70,052 $ 67,950 $ 144,534 $ 120,652 (1)Depreciation and amortization expenses included in our results of operations for the periods presented are as follows (in thousands): Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 June 30, 2026 June 30, 2025 Cost of revenue $ 17,385 $ 12,161 $ 32,759 $ 24,044 Research and development 887 799 1,725 1,479 Sales and marketing 5 27 10 63 General and administrative 1,642 1,662 3,267 3,553 Total depreciation and amortization $ 19,919 $ 14,649 $ 37,761 $ 29,139 (2)See Note 7 to the condensed consolidated financial statements for stock-based compensation expense included in our results of operations for the periods presented. (3)Non-GAAP adjustments do not have a material impact on our worldwide income tax provision due to the tax treatment of the non-GAAP adjustments reported, and our domestic valuation allowance position. Key Components of Our Results of Operations Revenue Our revenue consists of subscription and telecom as well as professional services. We consider our subscription and telecom to be recurring revenue. We charge our customers monthly subscription fees for access to our Intelligent CX Platform, primarily based on the number of licenses, as well as on a consumption basis for our AI solutions. We offer monthly, annual and multiple-year contracts to our customers, generally with 30 days’ notice required for limited reductions in the number of licenses or the level of consumption. Increases in the number of licenses or the level of consumption can be provisioned almost immediately. Subscription fees are generally billed monthly in advance, while usage fees are billed in arrears. Subscription fees are recognized on a straight-line basis over the applicable term, which is predominantly the monthly contractual billing period. Support activities include technical assistance for our solution and upgrades and enhancements on a when and if available basis, which are not billed separately. Usage fees are billed in arrears based on customer-specific per minute rate plans and are recognized as actual usage occurs. 34 Table of Contents In addition, we generate professional services revenue from assisting customers in implementing our solution and optimizing its use. These services include application configuration, system integration and education and training services. Professional services are primarily billed on a fixed-fee basis and are typically performed by us directly. However, our customers can choose to perform these services themselves, use one of our certified professional service providers, or engage their own third-party service providers to perform such services. Professional services are recognized as the services are performed using the proportional performance method, with performance measured based on labor hours, provided all other criteria for revenue recognition are met. We expect that new and continued macroeconomic challenges resulting from the impact of global tariff increases and potential future increases and announcements regarding same, as well as the impact of current and potential global conflicts, continued inflation, uncertainty regarding consumer spending, high interest rates, fluctuations in currency rates, and other factors, may harm our business. Cost of Revenue Our cost of revenue consists primarily of personnel costs, including stock-based compensation, fees that we pay to telecommunications providers for usage, Universal Service Fund, or USF, contributions and other regulatory costs, depreciation and related expenses of our servers and equipment, costs to build out and maintain co-location data centers, costs of public cloud-based data centers, cost of third party software that we resell, allocated office and facility costs, amortization of acquired technology, amortization of internal-use software development costs and lease amortization for finance leases. Cost of revenue can fluctuate based on a number of factors, including the fees we pay to telecommunications providers, which vary depending on our customers’ usage of our Intelligent CX Platform, the timing of capital expenditures and related depreciation charges and changes in headcount. We expect to continue investing in professional services, public cloud, cloud operations, customer support and network infrastructure to maintain high quality and availability of services, which we believe will result in absolute dollar increases in cost of revenue but we expect cost of revenue to fluctuate as a percentage of revenue in the near term, and to decline as a percentage of revenue in the long-term through economies of scale. Operating Expenses We classify our operating expenses as research and development, sales and marketing, and general and administrative expenses. Research and Development. Our research and development expenses consist primarily of salary and related expenses, including stock-based compensation, for personnel related to the development of new products, improvements and expanded features for our services, as well as quality assurance, testing, product management and allocated overhead. We expense research and development expenses as they are incurred except for internal use software development costs that qualify for capitalization. We believe that continued investment in our solution is important for our future growth, and we expect our research and development expenses to increase in absolute dollars and fluctuate as a percentage of revenue in the near and longer term. Sales and Marketing. Sales and marketing expenses consist primarily of salaries and related expenses, including stock-based compensation, for personnel in sales and marketing, amortization of deferred contract acquisition costs, as well as advertising, marketing, corporate communications, travel costs and allocated overhead. We believe it is important to continue investing in sales and marketing to continue to generate revenue growth, and we expect sales and marketing expenses to increase in absolute dollars and fluctuate as a percentage of revenue in the near and longer term as we continue to support our growth initiatives. General and Administrative. General and administrative expenses consist primarily of salary and related expenses, including stock-based compensation, for management, finance and accounting, legal, information systems and human resources personnel, professional fees, compliance costs, other corporate expenses and allocated overhead. We expect that general and administrative expenses will fluctuate in absolute dollars and as a percentage of revenue in the near term, but to increase in absolute dollars and decline as a percentage of revenue in the longer term. Results of Operations for the Three and Six Months Ended June 30, 2026 and 2025 Based on the condensed consolidated statements of operations and comprehensive income (loss) set forth in this Quarterly Report on Form 10-Q, the following table sets forth our operating results as a percentage of revenue 35 Table of Contents for the periods indicated: Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 June 30, 2026 June 30, 2025 Revenue 100 % 100 % 100 % 100 % Cost of revenue 47 % 45 % 45 % 45 % Gross profit 53 % 55 % 55 % 55 % Operating expenses: Research and development 13 % 14 % 13 % 14 % Sales and marketing 26 % 28 % 27 % 29 % General and administrative 14 % 14 % 12 % 13 % Total operating expenses 53 % 56 % 52 % 56 % Income (loss) from operations — % (1) % 3 % (1) % Other income (expense), net: Interest expense (1) % (2) % (1) % (1) % Interest income and other 2 % 3 % 2 % 3 % Total other income (expense), net 1 % 1 % 1 % 2 % Income before income taxes 1 % — % 4 % 1 % Provision for income taxes — % — % — % 1 % Net income 1 % — % 4 % — % Revenue Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Revenue $ 312,444 $ 283,269 $ 29,175 10 % $ 617,763 $ 562,974 $ 54,789 10 % The increase in revenue for the three and six months ended June 30, 2026 compared to the same period of 2025 was primarily attributable to our larger customers, driven by our sales and marketing activities and our improved brand awareness. Cost of Revenue Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Cost of revenue $ 145,700 $ 127,865 $ 17,835 14 % $ 280,492 $ 253,838 $ 26,654 11 % % of Revenue 47 % 45 % 45% 45% The increase in cost of revenue for the three months ended June 30, 2026 compared to the same period of 2025 was primarily due to a $7.6 million increase in third-party costs driven by increased customer activities, a $7.5 million increase in depreciation, data center and public cloud costs to support our growing capacity needs, a $4.3 million increase in amortization of capitalized internal-use software development costs, and a $1.6 million increase in consulting costs for global expansion, offset in part by a $2.8 million decrease in personnel-related costs primarily driven by a decrease in stock-based compensation costs. The increase in cost of revenue for the six months ended June 30, 2026 compared to the same period of 2025 was primarily due to a $14.5 million increase in third-party costs driven by increased customer activities, a $7.7 million increase in amortization of capitalized internal-use software development costs, a $7.6 million increase in depreciation, data center and public cloud costs to support our growing capacity needs, and a $2.3 million increase in consulting costs for global expansion, offset in part by a $3.9 million decrease in personnel-related costs primarily 36 Table of Contents driven by a decrease in stock-based compensation costs, and by a $0.7 million decrease in amortization of acquired intangible assets. Gross Profit Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Gross profit $ 166,744 $ 155,404 $ 11,340 7 % $337,271 $309,136 $28,135 9% % of Revenue 53 % 55 % 55% 55% The increase in gross profit for the three and six months ended June 30, 2026 compared to the same periods of 2025 was primarily due to increases in subscription and related revenues. We expect gross margin to increase in the long-term with long-term revenue growth outpacing continued investments in professional services, public cloud, cloud operations, customer support and network infrastructure. Operating Expenses Research and Development Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Research and development $ 42,068 $ 39,912 $ 2,156 5 % $ 81,744 $81,012 $732 1% % of Revenue 13% 14 % 13% 14% The increase in research and development expenses for the three months ended June 30, 2026 compared to the same period of 2025 was primarily due to a $1.3 million increase in staff augmentation costs, a $0.8 million increase in public cloud development costs, and a $0.3 million decrease in research and development costs (excluding stock-based compensation costs) that qualified for capitalization, offset in part by a $0.7 million decrease in personnel-related costs primarily due to a decrease in stock-based compensation costs. The increase in research and development expenses for the six months ended June 30, 2026 compared to the same period of 2025 was primarily due to a $1.9 million increase in staff augmentation costs and a $0.9 million increase in public cloud development costs, offset in part by a $2.1 million decrease in personnel-related costs primarily due to a decrease in stock-based compensation costs and a $0.5 million increase in research and development costs (excluding stock-based compensation costs) that qualified for capitalization. Sales and Marketing Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Sales and marketing $ 79,703 $ 80,668 $ (965) (1) % $ 159,192 $163,523 $(4,331) (3)% % of Revenue 26 % 28 % 27% 29% The decrease in sales and marketing expenses for the three months ended June 30, 2026 compared to the same period of 2025 was primarily due to a $5.8 million decrease in personnel-related costs mainly due to a decrease in stock-based compensation costs, offset in part by a $3.6 million increase in amortization of deferred contract acquisition costs driven by the growth in sales and bookings of our solution and by a $1.4 million increase in overall marketing spend. The decrease in sales and marketing expenses for the six months ended June 30, 2026 compared to the same period of 2025 was primarily due to an $11.2 million decrease in personnel-related costs mainly due to a decrease in 37 Table of Contents stock-based compensation costs, and a $0.7 million decrease in travel costs as a result of reduced business travel, offset in part by a $7.4 million increase in amortization of deferred contract acquisition costs driven by the growth in sales and bookings of our solution. General and Administrative Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) General and administrative $ 42,996 $ 36,385 $ 6,611 18 % $75,865 $71,590 $4,275 6% % of Revenue 14% 14% 12% 13% The increase in general and administrative expenses for the three months ended June 30, 2026 compared to the same period of 2025 was primarily due to an $8.4 million increase in impairment charge as a result of the initiation of a plan to consolidate our corporate headquarters from two floors to a single floor in May 2026, offset in part by a $1.4 million decrease in personnel-related costs primarily due to a decrease in stock-based compensation costs. The increase in general and administrative expenses for the six months ended June 30, 2026 compared to the same period of 2025 was primarily due to an $8.4 million increase in impairment charge as a result of the initiation of a plan to consolidate our corporate headquarters from two floors to a single floor in May 2026, offset in part by a $2.9 million decrease in personnel-related costs primarily due to a decrease in stock-based compensation costs. The remaining decrease was primarily due to a reduction in overall general and administrative spend during this period as a result of our ongoing cost-reduction and productivity initiatives. Other Income (Expense), Net Three Months Ended Six Months Ended June 30, 2026 June 30, 2025 $ Change % Change June 30, 2026 June 30, 2025 $ Change % Change (in thousands, except percentages) Interest expense $ (3,507) $ (3,820) $ 313 (8) % $ (6,649) $ (7,935) $ 1,286 (16) % Interest income and other 5,838 7,917 (2,079) (26) % 11,050 18,220 (7,170) (39) % Total other income (expense), net $ 2,331 $ 4,097 $ (1,766) (43) % $ 4,401 $ 10,285 $ (5,884) (57) % % of Revenue 1 % 1 % 1 % 2 % The decrease in interest expense for the three and six months ended June 30, 2026 compared to the same periods of 2025 was primarily due to the maturity of the 2025 convertible senior notes on June 1, 2025. The decrease in interest income and other for the three and six months ended June 30, 2026 compared to the same periods of 2025 was due to lower investable balances primarily resulting from cash paid in connection with the maturity of the 2025 convertible senior notes and the repurchases of our common stock, offset in part by an increase in foreign currency transaction gains. Liquidity and Capital Resources To date, we have financed our operations primarily through sales of our solution, net proceeds from our equity and debt financings, including the issuance of convertible senior notes in March 2024, May and June 2020 and May 2018, and lease facilities. As of June 30, 2026, we had $722.1 million in working capital, which included $187.3 million in cash and cash equivalents and $466.8 million in marketable investments. Our 2025 convertible senior notes matured on June 1, 2025, and we settled our obligations with respect to the 2025 convertible senior notes through a cash payment of $434.4 million in connection therewith. Our intent is that all marketable investments are available for use in our current operations, including marketable investments with maturity dates greater than one year from June 30, 2026. In March 2024, we issued $747.5 million aggregate principal amount of our 2029 convertible senior notes in a private offering. The 2029 convertible senior notes mature on March 15, 2029 and are our senior unsecured obligations. The 2029 convertible senior notes bear interest at a fixed rate of 1.00% per annum, payable 38 Table of Contents semiannually in arrears on March 15 and September 15 of each year, beginning on September 15, 2024. The total net proceeds from the issuance of the 2029 convertible senior notes, after deducting initial purchasers' discounts and commissions and estimated debt issuance costs, were approximately $728.8 million. In connection with the issuance of the 2029 convertible senior notes, we used part of the net proceeds from the issuance to repurchase approximately $313.1 million aggregate principal amount of our then outstanding 2025 convertible senior notes in privately-negotiated transactions for aggregate cash consideration of approximately $304.9 million. In connection with the issuance of the 2029 convertible senior notes, we also entered into privately negotiated capped call transactions with certain financial institutions. We believe our existing cash and cash equivalents will be sufficient to meet our working capital and capital expenditure needs for at least the next 12 months. We plan to continue to finance our operations in the future primarily through sales of our solution, net proceeds from equity and debt financings, and lease facilities. Our future capital requirements will depend on many factors including our growth rate, continuing market acceptance of our solution, the strength of the global economy, customer retention, growth within our installed base, our ability to gain new customers, the timing and extent of spending to support research and development efforts, the outcome of any pending or future litigation or other claims by third parties or governmental entities, the expansion of sales and marketing activities and personnel, the introduction of new and enhanced offerings, expenses incurred in expanding our operations internationally, and the effect of the length and severity of the continued macroeconomic challenges resulting from the impact of global tariff increases and potential future increases and announcements regarding same, as well as the impact of current and potential global conflicts, on these or other factors. We may also acquire or invest in complementary businesses, technologies and intellectual property rights, such as our acquisitions of Aceyus in August 2023 and Acqueon in August 2024, which may increase our use of cash and future capital requirements, both to pay acquisition costs and to support our combined operations. We may raise additional capital through equity or debt financings at any time to fund these or other requirements. However, we may not be able to raise additional capital through equity or debt financings when needed on terms acceptable to us or at all, depending on our financial performance and condition, economic and market conditions, the trading price of our common stock, and other factors, including the length and severity of the current challenging macroeconomic environment and fluctuations in the financial markets resulting from the impact of global tariff increases and potential future increases and announcements regarding same, as well as the impact of current and potential global conflicts. If we are unable to raise additional capital as needed, our business, operating results and financial condition could be harmed. In addition, if our operating performance is below our expectations, our liquidity and ability to operate our business also could be harmed. If we raise additional funds by issuing equity or equity-linked securities, the ownership of our existing stockholders would be diluted. If we raise additional funds through the incurrence of additional indebtedness, we will be subject to increased debt service obligations and could also be subject to restrictive covenants and other operating restrictions that could negatively impact our ability to operate our business. Repurchase Programs 2025 Repurchase Program In October 2025, our Board of Directors approved the 2025 Repurchase Program, which authorized the repurchase of up to $150.0 million of our common stock through December 31, 2027. The shares may be repurchased at management’s discretion, either on the open market or in privately negotiated block transactions. Management’s decision to repurchase shares will depend on price, blackout periods and other corporate developments. Purchases may occur from time to time and no maximum purchase price has been set. As part of the 2025 Repurchase Program, we entered into an ASR program (the "2025 ASR Program") with JPMorgan Chase Bank, National Association N.A. ("JPM") on November 11, 2025. Under the terms of the 2025 ASR Program, on November 12, 2025, we made an aggregate payment of $50 million and received an initial delivery of 1,926,782 shares of our common stock at an initial price of $20.76 per share, representing approximately 73% of the total number of shares of our common stock purchased under the 2025 ASR program. The 2025 ASR Program was completed on February 2, 2026, which resulted in delivery of 701,517 additional shares to us. The final share settlement was based on the average daily volume-weighted average price of our shares, netted against the initial delivery. The shares received were immediately retired and recorded as a reduction to additional paid-in-capital within stockholders’ equity. In March 2026, we repurchased 578,742 shares under the 2025 Repurchase Program at an average share price of $17.28 for an aggregate payment of $10.0 million. We entered into an additional $90 million ASR program (the “2026 ASR Program”) on May 4, 2026 with JPM to repurchase the remaining authorized amount under the 2025 Repurchase Program. Under the terms of the 2026 ASR Program, on May 5, 2026, we made an aggregate payment of $90 million and received an initial delivery 39 Table of Contents of 3,084,833 shares of our common stock at an initial price of $23.34 per share, representing approximately 80% of the total number of shares of our common stock expected to be purchased under the 2026 ASR Program. The shares received were immediately retired and recorded as a reduction to additional paid-in-capital within stockholders' equity. Given our ability to settle in shares, as described below, the remaining $18 million prepaid forward contract was classified as a reduction to additional-paid-in-capital upon issuance and as of June 30, 2026. The final settlement of the 2026 ASR Program is expected to occur in the third quarter of 2026. Under the ASR programs, upon settlement, we were permitted to either receive additional shares of common stock from JPM or were required to deliver additional shares of common stock or cash to JPM, at our election. The final number of shares we repurchased was based on the average of the daily volume-weighted average prices of our common stock during the term of the ASR programs, less a discount and subject to adjustments pursuant to the terms and conditions of the ASR programs. Cash settlement was not mandatory pursuant to the terms of the ASR programs. As of June 30, 2026, no amount remained available under the 2025 Repurchase Program. 2026 Repurchase Program On April 30, 2026, we announced that our Board of Directors approved a new share repurchase program (the “2026 Repurchase Program”), which authorized the repurchase of up to an additional $200.0 million of our common stock and has no expiration date. Repurchases under the 2026 Repurchase Program will be made pursuant to open market purchases, solicited or unsolicited privately negotiated transactions, accelerated share repurchase transactions, and may be effected pursuant to 10b5-1 plans, and in compliance with applicable securities laws and other requirements. The 2026 Repurchase Program will be funded using our cash on hand and future cash flow generation. The timing, manner, price, and amount of repurchases under the 2026 Repurchase Program is subject to the discretion of our management. We are not obligated to acquire a specified number of shares under the 2026 Repurchase Program, which may be suspended, modified, or terminated at any time, without prior notice. The shares received will be immediately retired and recorded as a reduction to additional paid-in-capital within stockholders’ equity. As of June 30, 2026, $200.0 million remained available under the 2026 Repurchase Program. Cash Flows The following table summarizes our cash flows for the periods presented (in thousands): Six Months Ended June 30, 2026 June 30, 2025 Net cash provided by operating activities $ 105,998 $ 83,445 Net cash (used in) provided by investing activities (42,442) 191,063 Net cash used in financing activities (108,261) (431,125) Net decrease in cash, cash equivalents and restricted cash $ (44,705) $ (156,617) Cash Flows from Operating Activities Cash provided by operating activities is primarily influenced by our personnel-related expenditures, data center and telecommunications carrier costs, office and facility related costs, USF contributions and other regulatory costs and the amount and timing of customer payments. If we continue to improve our financial results, we expect net cash provided by operating activities to increase. Our largest source of operating cash inflows is cash collections from our customers for subscription and telecom services. Payments from customers for these services are typically received monthly. Net cash provided by operating activities was $106.0 million during the six months ended June 30, 2026. Net cash provided by operating activities resulted from our net income of $21.8 million, adjustments to reconcile net income to net cash provided by operating activities of $172.7 million, primarily consisting of $65.6 million of stock-based compensation, $48.4 million of amortization of deferred contract acquisition costs, $37.8 million of depreciation and amortization, $10.7 million of reduction in the carrying amount of right-of-use assets, $8.5 million impairment charges of long-lived assets, and $1.8 million of amortization of issuance costs on our convertible senior 40 Table of Contents notes, partially offset by use of cash for operating assets and liabilities of $(88.5) million primarily due to the timing of cash payments to vendors and cash receipts from customers and $(2.3) million accretion of discount on marketable investments. Net cash provided by operating activities was $83.4 million during the six months ended June 30, 2025. Net cash provided by operating activities resulted from our net income of $1.7 million, adjustments to reconcile net income to net cash provided by operating activities of $161.4 million, primarily consisting of $81.1 million of stock-based compensation, $41.5 million of amortization of deferred contract acquisition costs, $29.1 million of depreciation and amortization, $10.1 million of reduction in the carrying amount of right-of-use assets, and $2.7 million of amortization of issuance costs on our convertible senior notes, partially offset by use of cash for operating assets and liabilities of $(79.7) million primarily due to the timing of cash payments to vendors and cash receipts from customers and $(5.3) million accretion of discount on marketable investments. Cash Flows from Investing Activities Net cash used in investing activities of $(42.4) million in the six months ended June 30, 2026 was comprised of $(199.6) million related to purchases of marketable investments, $(22.9) million in capital expenditures, and $(18.5) million in capitalized software development costs, offset in part by $198.6 million related to cash proceeds from sales and maturities of marketable investments. Net cash provided by investing activities of $191.1 million in the six months ended June 30, 2025 was comprised of $533.2 million related to cash proceeds from sales and maturities of marketable investments, offset in part by $315.1 million related to purchases of marketable investments, $18.7 million in capitalized software development costs and $8.2 million in capital expenditures. Cash Flows from Financing Activities Net cash used in financing activities of $(108.3) million in the six months ended June 30, 2026 was from $(100.0) million of cash paid for the repurchase of our common stock, $(10.8) million of principal payments on financing arrangements, and $(4.9) million of payments related to finance leases, offset in part by $7.0 million from the sale of common stock under our employee stock purchase plan and $0.4 million in proceeds from the exercise of common stock options. Net cash used in financing activities of $(431.1) million in the six months ended June 30, 2025 was primarily related to $434.4 million of cash paid in connection with the maturity of the 2025 convertible senior notes and $4.7 million of payments related to finance leases, offset in part by $7.9 million from the sale of common stock under our employee stock purchase plan. Critical Accounting Policies and Estimates Our condensed consolidated financial statements are prepared in accordance with U.S. GAAP. The preparation of these financial statements requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenue, expenses and related disclosures. On an ongoing basis, we evaluate our estimates and assumptions. Our actual results may differ from these estimates under different assumptions or conditions. There have been no material changes to our critical accounting policies and estimates from those disclosed in our Annual Report on Form 10-K for the fiscal year ended December 31, 2025 filed with the SEC on February 20, 2026. Recent Accounting Pronouncements Refer to Note 1 of the notes to condensed consolidated financial statements included in this report. Contractual and Other Obligations Our material cash requirements include the following contractual and other obligations. Convertible Senior Notes 41 Table of Contents In May and June 2020, we issued $747.5 million aggregate principal amount of our 2025 convertible senior notes in a private offering. The 2025 convertible senior notes matured on June 1, 2025, and we settled our obligations with respect to the 2025 convertible senior notes in cash in connection therewith. Prior to maturity, the 2025 convertible senior notes bore interest at a fixed rate of 0.50% per annum, payable semiannually in arrears on June 1 and December 1 of each year, beginning December 1, 2020. The total net proceeds from the offering, after deducting initial purchasers’ discounts and commissions and estimated debt issuance costs, were approximately $728.8 million. In March 2024, we issued $747.5 million aggregate principal amount of our 2029 convertible senior notes in a private offering. In connection with the issuance of the 2029 convertible senior notes, we used part of the net proceeds from the issuance to repurchase approximately $313.1 million aggregate principal amount of our 2025 convertible senior notes. The 2029 convertible senior notes mature on March 15, 2029 and are our senior unsecured obligations. The 2029 convertible senior notes bear interest at a fixed rate of 1.00% per annum, payable semiannually in arrears on March 15 and September 15 of each year, beginning on September 15, 2024. The total net proceeds from the issuance of the 2029 convertible senior notes, after deducting initial purchasers' discounts and commissions and debt issuance costs, were approximately $728.8 million. As of June 30, 2026, the aggregate principal amount outstanding of our 2029 convertible senior notes was $747.5 million. See Note 6 to the condensed consolidated financial statements included in this report for further details. Leases We have leases for offices, data centers and computer and networking equipment that expire at various dates through 2031. Our leases have remaining terms of one to seven years. Some of the leases include an option to extend the leases for up to one to five years, and some of the leases include the option to terminate the leases upon 30-days' notice. We had outstanding operating lease obligations of $61.7 million as of June 30, 2026, with $8.6 million payable in the remainder of 2026, $28.5 million payable within one to three years, $22.9 million payable within three to five years, and $1.7 million payable after five years. We also had outstanding finance lease obligations of $12.1 million as of June 30, 2026, with $4.4 million payable in the remainder of 2026, $7.4 million payable within one to three years, and $0.3 million payable within three to five years. We entered into additional three-year equipment finance lease agreements and recognized $1.6 million right of use assets during the three months ended June 30, 2026, which were reported within Finance lease right-of-use assets and are being depreciated on a straight-line basis over the lease term. As a result, we also recognized short-term lease liabilities of $0.5 million within Finance lease liabilities and long-term lease liabilities of $1.1 million within Finance lease liabilities - less current portion during these periods. See Note 12 to the condensed consolidated financial statements included in this report for further details. Cloud Services and Software and Maintenance As of June 30, 2026, we had outstanding cloud services and software and maintenance agreement commitments totaling $125.4 million, of which $14.7 million is expected to be purchased in the remainder of 2026, $107.3 million is expected to be purchased in 2027 and 2028, and the remaining $3.4 million is expected to be purchased in 2029. Hosting and Telecommunication Usage Services We have agreements with third parties to provide co-location hosting and telecommunication usage services. The agreements require payments per month for a fixed period of time in exchange for certain guarantees of network and telecommunication availability. As of June 30, 2026, we had outstanding hosting and telecommunication usage services obligations of $12.4 million, with $3.0 million payable in the remainder of 2026, $7.5 million payable in 2027 and 2028, and $1.9 million payable in 2029 and 2030. Other Agreements During the first half of 2026, we entered into a $53.9 million five-year agreement for data center support and maintenance services, which was financed through a non-interest bearing financing arrangement. In accordance with ASC 835-30, the financing arrangement was recorded as a liability at its present value of $48.3 million using an imputed interest. We are obligated to make five installment payments of $10.8 million annually, with the first payment made upon execution of the agreement in March 2026, and the remaining four annual payments due from 42 Table of Contents March 2027 through March 2030. The current and long-term portions of this obligation were $10.8 million and $27.4 million, respectively, as of June 30, 2026. During the first half of 2026, we executed a reseller agreement with a total commitment of $9.0 million, a term from March 31, 2026 to March 31, 2027, with a total remaining commitment of $6.3 million as of June 30, 2026. Indemnification Agreements In the ordinary course of business, we enter into agreements of varying scope and terms pursuant to which we agree to indemnify customers, vendors, lessors, business partners and other parties with respect to certain matters, including, but not limited to, losses arising out of breach of such agreements, services to be provided by us or from intellectual property infringement claims made by third parties. We have received indemnification demands, and will likely continue to receive demands, from customers regarding our intellectual property indemnification obligations under these contracts. In addition, we have entered into indemnification agreements with our directors, officers and certain employees that will require us, among other things, to indemnify them against certain liabilities that may arise by reason of their status or service as directors, officers or employees. There are no claims that we are aware of that could have a material effect on our consolidated balance sheets, consolidated statements of operations and comprehensive income (loss), or consolidated statements of cash flows. Contingencies — Legal and Regulatory We are subject to certain legal and regulatory proceedings, and from time to time may be involved in a variety of claims, lawsuits, investigations, and proceedings relating to contractual disputes, intellectual property rights, employment matters, regulatory compliance matters, and other litigation matters relating to various claims that arise in the normal course of business. We determine whether an estimated loss from a contingency should be accrued by assessing whether a loss is deemed probable and can be reasonably estimated. We assess our potential liability by analyzing specific litigation and regulatory matters using reasonably available information. We develop our views on estimated losses in consultation with inside and outside counsel, which involves a subjective analysis of potential results and outcomes, assuming various combinations of appropriate litigation and settlement strategies. Legal fees are expensed in the period in which they are incurred. We are currently party to the following actions: On December 4, 2024, a purported holder of our securities filed a putative class action complaint against us, our then-current Chief Executive Officer, and our then-current Chief Financial Officer in the United States District Court for the Northern District of California alleging violations of Section 10(b) and 20(a) of the Securities Exchange Act of 1934 and Rule 10b-5, promulgated thereunder, based on alleged false and/or misleading statements or omissions regarding us and our business and seeking unspecified damages on behalf of all persons and entities (subject to specified exceptions) that purchased or otherwise acquired our securities, including call options, from June 4, 2024, through the close of trading on August 8, 2024. On February 3, 2025, Lucid Alternative Fund, LP moved to be appointed lead plaintiff of this action pursuant to the Private Securities Litigation Reform Act of 1995. On March 18, 2025, the court appointed Lucid Alternative Fund, LP as lead plaintiff and approved lead plaintiff’s selection of lead counsel. Per the court’s subsequent order on March 27, 2025, Lucid Alternative Fund, LP filed an amended complaint on May 30, 2025. We moved to dismiss the amended complaint on July 29, 2025, and the court took the motion under submission after oral argument on December 18, 2025. On February 23, 2026, the court granted in part and denied in part Defendants' motion to dismiss. We cannot predict the duration or outcome of this lawsuit at this time. As a result, we are unable to estimate the reasonably possible loss or range of reasonably possible losses arising from this lawsuit. We intend to vigorously defend this lawsuit. On March 18, 2025, a related shareholder derivative action was filed in the United States District Court for the Northern District of California on behalf of nominal defendant Five9, Inc. and against its directors and certain of its officers seeking to assert claims for breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets, and for contribution under Sections 10(b) and 21D of the Securities Exchange Act of 1934. The Company was served with the complaint on March 20, 2025. The action was stayed pending the resolution of the motion to dismiss in the securities action. On February 27, 2026, a separate and related shareholder derivative action was filed again in the United States District Court for the Northern District of California on behalf of nominal defendant Five9, Inc. and against its directors and certain of its officers seeking to assert claims for breach of fiduciary duty, unjust enrichment, abuse of control, gross mismanagement, and waste of corporate assets, and for contribution under Sections 10(b) and 21D of the Securities Exchange Act of 1934. On March 9, 2026, all parties filed a stipulation with the court to consolidate the two derivative actions, which the court so ordered on March 17, 2026. On May 20, 2026, the court entered an order on the parties’ stipulation staying the derivative action. 43 Table of Contents On March 24, 2026, a related shareholder derivative action was filed in the United States District Court for the District of Delaware on behalf of nominal defendant Five9, Inc. and against its directors and certain of its officers seeking to assert claims for breaches of fiduciary duties, gross mismanagement, waste of corporate assets, unjust enrichment, and violation of Section 14(a) of the Securities Exchange Act of 1934. On April 15, 2026, the court entered an order on the parties' stipulation staying the derivative action. 44 Table of Contents