Forward-Looking Information The statements included in this quarterly report regarding future financial performance and results of operations and other statements that are not historical facts are forward-looking statements within the meaning of Section 27A of the United States (“U.S.”) Securities Act of 1933 and Section 21E of the U.S. Securities Exchange Act of 1934. Forward-looking statements in this quarterly report include, but are not limited to, statements about the following subjects: ◾the effect of any disputes and actions with respect to production levels by, among or between major oil and gas producing countries and any expectations we may have with respect thereto; ◾our results of operations, our cash flow from operations, our revenue efficiency and other performance indicators and optimization of rig-based spending; ◾the offshore drilling market, including the effects of variations in commodity prices, supply and demand, utilization rates, dayrates, customer drilling programs, customer strategy, stacking and reactivation of rigs, the impact of changes to regulations in jurisdictions in which we operate and changes in the global economy or market outlook for our industry, or the various geographies in which we operate; ◾customer drilling contracts, including contract backlog, force majeure provisions, contract awards, commencements, extensions, cancellations, terminations, renegotiations, contract option exercises, contract revenues, early termination fees, indemnity provisions and rig mobilizations; ◾the addition of renewable or other energy alternatives to meet local, regional or global demand for energy, and efforts by us or our customers, to reduce greenhouse gas emissions or operating intensity thereof; ◾liquidity, including availability under our Secured Credit Facility, as defined in this periodic report, and adequacy of cash flows for our obligations; ◾debt, including interest rates, credit ratings and our evaluation or decisions with respect to any potential liability management transactions or strategic alternatives intended to prudently manage our liquidity, debt maturities and other aspects of our capital structure; ◾upgrade, shipyard, reactivations and other capital projects, including the level of expected capital expenditures and the timing and cost of completing capital projects, relinquishment or abandonment, expected downtime and lost revenues; ◾the cost and timing of acquisitions and reactivations, and the proceeds and timing of dispositions; ◾ our expectations regarding the timing, completion and anticipated benefits of the proposed business combination (the “Business Combination”) with Valaris Limited, an exempted company limited by shares incorporated under the laws of Bermuda (“Valaris”); ◾tax matters, including our effective tax rate, uncertain tax positions, changes in tax laws, treaties and regulations, tax assessments, tax incentive programs and liabilities for tax issues in the tax jurisdictions in which we operate or have a taxable presence; ◾legal and regulatory matters, including results and effects of current or potential legal proceedings and governmental audits and assessments, outcomes and effects of internal and governmental investigations, customs and environmental matters; ◾insurance matters, risk tolerance and risk response, including adequacy and solvency of insurance, renewal of insurance, insurance proceeds and cash investments of our wholly owned captive insurance company; ◾effects of accounting changes and adoption of accounting policies; and ◾investment in recruitment, retention and personnel development initiatives, the timing of, and other matters concerning, severance payments, benefit payments and maintaining agreements with labor unions. Forward-looking statements in this quarterly report are identifiable by use of the following words and other similar expressions: ◾ anticipates ◾ budgets ◾ estimates ◾ forecasts ◾ may ◾ plans ◾ projects ◾ should ◾ believes ◾ could ◾ expects ◾ intends ◾ might ◾ predicts ◾ scheduled ​ ​ Such statements are subject to numerous risks, uncertainties and assumptions, including, but not limited to: ◾those described under “Item 1A. Risk Factors” included in Part I of our annual report on Form 10-K for the year ended December 31, 2025; ◾the effects of actions by, or disputes among or between, members of the Organization of the Petroleum Exporting Countries and other oil and natural gas producing countries with respect to production levels or other matters related to the prices of oil and natural gas; ◾the adequacy of and access to our sources of liquidity; ◾our inability to renew drilling contracts at comparable, or improved, dayrates and to obtain drilling contracts for our rigs that do not have contracts; ◾our operational performance; ◾the cancellation of drilling contracts currently included in our reported contract backlog; ◾losses on impairment of long-lived assets; ◾shipyard and other delays; ◾the results of meetings of our shareholders; ◾changes in political, social and economic conditions, including the effects of political and military disputes; ◾the possibility of changes in tax, environmental, trade, immigration and other laws, regulations and policies, including the imposition of tariffs, economic or trade sanctions or other trade barriers and actions of government that impact, whether directly or indirectly, oil and gas operations; ◾the effect and results of litigation, regulatory matters, settlements, audits, assessments and contingencies; ◾the availability of borrowings under our Secured Credit Facility, as well as the timing of any amendments thereto; and ◾other factors discussed in this quarterly report and in our other filings with the U.S. Securities and Exchange Commission (“SEC”), which are available free of charge on the SEC website at www.sec.gov. The foregoing risks and uncertainties are beyond our ability to control, and in many cases, we cannot predict the risks and uncertainties that could cause our actual results to differ materially from those indicated by the forward-looking statements. Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those indicated. All subsequent written and oral forward-looking statements attributable to us or to persons acting on our behalf are expressly qualified in their entirety by reference to these risks and uncertainties. You should not place undue reliance on forward-looking statements, each of which speaks only as of the date of the particular statement. We expressly disclaim any obligations or undertaking to release publicly any updates or revisions to any forward-looking statement to reflect any change in our expectations or beliefs with regard to the statement or any change in events, conditions or circumstances on which any forward-looking statement is based, except as required by law. - 13 - Table of Contents Introduction Transocean Ltd. (together with its subsidiaries and predecessors, unless the context requires otherwise, “Transocean,” “we,” “us” or “our”) is a leading international provider of offshore contract drilling services for oil and gas wells. As of July 28, 2026, we owned or had partial ownership interests in and operated 27 mobile offshore drilling units, consisting of 20 ultra-deepwater drillships and seven harsh environment semisubmersibles. We provide, as our primary business, contract drilling services in a single operating segment, which involves contracting our mobile offshore drilling rigs, related equipment and work crews to drill oil and gas wells. We specialize in technically demanding regions of the global offshore drilling business with a particular focus on ultra-deepwater and harsh environment drilling services. Our drilling fleet is one of the most versatile fleets in the world, consisting of drillships and semisubmersible floaters used in support of offshore drilling activities and offshore support services on a worldwide basis. We perform contract drilling services by deploying our high-specification fleet in a single, global market that is geographically dispersed in oil and gas exploration and development areas throughout the world. Although rigs can be moved from one region to another, the cost of moving rigs and the availability of rig-moving vessels may cause the supply and demand balance to fluctuate somewhat between regions. Still, significant variations between regions do not tend to persist long term because of rig mobility. The location of our rigs and the allocation of resources to operate, build or upgrade our rigs are determined by the activities and needs of our customers. Our discussion and analysis of our financial condition, operating results and liquidity and capital resources are based upon, and should be read in conjunction with, our condensed consolidated financial statements and the notes thereto, included under “Item 1. Financial Statements” in this quarterly report on Form 10-Q and with “Part II. Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our annual report on Form 10-K for the year ended December 31, 2025. Significant Events Agreement to acquire Valaris—On February 9, 2026, we and Valaris entered into a Business Combination Agreement (the "Agreement") providing for the Business Combination. Pursuant to the Agreement, and on the terms and subject to the conditions thereof, we will acquire all of the issued and outstanding common shares, par value $0.01 each, of Valaris (the “Valaris Shares”) in exchange for Transocean Ltd. shares, par value $0.10 each, at an exchange ratio of 15.235 Transocean Ltd. shares for each Valaris Share. See Notes to Consolidated Financial Statements—Note 1—Business. Disposal of assets—In the six months ended June 30, 2026, we completed the sale of the ultra-deepwater drillships Deepwater Champion and Discoverer India, together with related assets, for aggregate net cash proceeds of $27 million, including $3 million received as a deposit in the year ended December 31, 2025. In July 2026, we completed the sale of the harsh environment semisubmersible Henry Goodrich, together with related assets, for net cash proceeds of $3 million. See “—Liquidity and Capital Resources.” Debt redemption—In March 2026, we made a cash payment of $365 million, including an early redemption premium, to retire the outstanding $358 million aggregate principal amount of the 8.375% senior secured notes due February 2028 (the “8.375% Senior Secured Notes”). See “—Liquidity and Capital Resources.” Exercised warrants—In April 2026, we issued 9.7 million Transocean Ltd. shares as net settlement of 22.2 million warrants exercised by holders to purchase our shares. See “—Liquidity and Capital Resources.” Outlook Drilling market—Our industry outlook remains positive, supported by numerous long-term forecasts indicating that hydrocarbons will continue to be the dominant source of energy for the foreseeable future. Indeed, many operators are increasingly redirecting capital investment to the exploration and production of oil and gas, and away from non-core activities. While we expect our customers to continue to be disciplined in their deployment of capital, and we believe that they will continue to invest an increasing portion of their budgets in offshore drilling, and particularly in deepwater, where resource potential, production longevity, and project economics are favorable, to achieve their production and reserve replacement targets. More recently, persistent geopolitical instability, including the conflict in the Middle East, has highlighted significant hydrocarbon constraints in the supply chain. As a result, governmental policy makers are reassessing their energy strategies and are prioritizing energy security, taking steps to improve the diversity and resiliency of their supply portfolios, including the exploitation of hydrocarbons from domestic sources. These shifts underscore the continued need for accessible, reliable, cost-effective, and transportable energy sources, with offshore oil and gas increasingly viewed as a key strategic asset. Although hydrocarbon prices remain sensitive to geopolitical events, macroeconomic conditions and policy decisions, and short-term supply fluctuations, we expect the overall economics of deepwater and harsh-environment projects to remain attractive. These fields continue to generate competitive economic returns and are generally of lower carbon intensity compared to many other hydrocarbon sources. - 14 - Table of Contents Consistent with our prior expectations, overall tendering activity and contract awards increased during the first half of 2026 and additional contract awards are anticipated for projects commencing in 2027 and 2028. Demand for ultra-deepwater rigs remains robust and is expanding geographically, with incremental opportunities emerging, for example, in West Africa, the Mediterranean Sea, Southeast Asia and India. High-specification drillships that have historically operated in the U.S. Gulf or Brazil are expected to mobilize to these regions as contract durations and commercial conditions become increasingly attractive. Similarly, we expect demand for harsh environment rigs to remain strong through the end of the decade, driven primarily by activity in Norway – the largest market for these units – and by opportunities emerging in new geographies suited for harsh-environment capable rigs. Several high-specification semisubmersible rigs that previously mobilized to other harsh environment regions, such as Namibia, the Black Sea, and Australia, have or are expected to return to the Norwegian North Sea as project requirements and market conditions continue to improve. Fleet status—We refer to the availability of our rigs in terms of the uncommitted fleet rate. The uncommitted fleet rate is defined as the number of uncommitted days divided by the total number of rig calendar days in the measurement period, expressed as a percentage. An uncommitted day is defined as a calendar day during which a rig is idle or stacked, is not contracted to a customer and is not committed to a shipyard. The uncommitted fleet rates exclude the effect of priced options. As of August 5, 2026, the uncommitted fleet rates for the remainder of 2026 and each of the four years in the period ending December 31, 2030 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 ​ 2027 ​ 2028 ​ 2029 ​ 2030 ​ Uncommitted fleet rate ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ultra-deepwater floaters ​ 26 % ​ 36 % ​ 70 % ​ 81 % ​ 93 % ​ Harsh environment floaters ​ 3 % ​ 18 % ​ 66 % ​ 86 % ​ 93 % ​ ​ ​ Performance and Other Key Indicators Contract backlog—We believe our contract backlog provides an indicator of our future revenue-earning opportunities. Contract backlog is defined as the maximum contractual operating dayrate multiplied by the number of days remaining in the firm contract period, including certain performance-based provisions for which achievement is probable, and excluding provisions for mobilization, demobilization, contract preparation, other incentive provisions or reimbursement revenues, which are not expected to be material to our contract drilling revenues. The contract backlog represents the maximum contract drilling revenues that can be earned considering the reported operating dayrate in effect during the firm contract period. The contract backlog for our fleet was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ August 5, ​ May 4, ​ February 19, ​ ​ ​ 2026 ​ 2026 ​ 2026 ​ ​ ​ (in millions) Contract backlog ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ultra-deepwater floaters ​ $ 4,816 $ 5,221 $ 4,477 ​ Harsh environment floaters ​ ​ 1,916 ​ ​ 1,907 ​ ​ 1,587 ​ Total contract backlog $ 6,732 $ 7,128 $ 6,064 ​ Our contract backlog includes only firm commitments, which are represented by signed drilling contracts or, in some cases, by other definitive agreements awaiting contract execution. It does not include conditional agreements and options to extend firm commitments. In June 2026, we entered into an agreement with Equinor ASA, conditional upon receipt of license approvals, for three harsh environment semisubmersible rigs. The contract, once approved, represents $1.0 billion of incremental contract backlog, excluding additional services, which is not included in the contract backlog presented above. The contractual operating dayrate may be higher than the actual dayrate we ultimately receive because an alternative contractual dayrate, such as a waiting-on-weather rate, repair rate, standby rate or force majeure rate, may apply under certain circumstances, or because of a number of factors, including rig downtime or suspension of operations. In certain contracts, the actual dayrate may be reduced to zero if, for example, repairs extend beyond a stated period of time. Average daily revenue—We believe average daily revenue provides a comparative measurement unit for our revenue-earning performance. Average daily revenue is defined as operating revenues, excluding revenues for contract terminations, reimbursements and contract intangible amortization, earned per operating day. An operating day is defined as a day for which a rig is contracted to earn a dayrate during the firm contract period after operations commence. The average daily revenue for our fleet was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ June 30, ​ March 31, ​ June 30, ​ ​ ​ 2026 ​ 2026 ​ 2025 ​ Average daily revenue ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Ultra-deepwater floaters ​ $ 455,500 ​ $ 480,700 ​ $ 457,200 ​ Harsh environment floaters ​ $ 510,000 ​ $ 463,800 ​ $ 462,400 ​ Total fleet average daily revenue ​ $ 472,500 $ 475,600 ​ $ 458,600 ​ - 15 - Table of Contents Our average daily revenue fluctuates relative to market conditions and our revenue efficiency. The average daily revenue may be affected by incentive performance bonuses or penalties or demobilization fee revenues. Revenues for a newbuild unit are included in the calculation when the rig commences operations upon acceptance by the customer. We remove a rig from the calculation upon disposal or classification as held for sale, unless we continue to operate the rig, in which case we remove the rig upon completion or novation of the contract. Revenue efficiency—We believe revenue efficiency measures our ability to ultimately convert our contract backlog into revenues. Revenue efficiency is defined as actual operating revenues, excluding revenues for contract terminations and reimbursements, for the measurement period divided by the maximum revenue calculated for the measurement period, expressed as a percentage. Maximum revenue is defined as the greatest amount of contract drilling revenues the drilling unit could earn for the measurement period, excluding revenues for incentive provisions, reimbursements and contract terminations. The revenue efficiency rates for our fleet were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ June 30, ​ March 31, ​ June 30, ​ ​ ​ 2026 ​ 2026 ​ 2025 Revenue efficiency ​ ​ ​ ​ ​ ​ ​ ​ ​ Ultra-deepwater floaters ​ 95.7 % ​ 97.6 % ​ 96.7 % ​ Harsh environment floaters ​ 99.5 % ​ 96.7 % ​ 96.3 % ​ Total fleet average revenue efficiency ​ 97.0 % ​ 97.3 % ​ 96.6 % ​ Our revenue efficiency rate varies due to revenues earned under alternative contractual dayrates, such as a waiting-on-weather rate, repair rate, standby rate, force majeure rate or zero rate, that may apply under certain circumstances. Our revenue efficiency rate is also affected by incentive performance bonuses or penalties. We include newbuilds in the calculation when the rigs commence operations upon acceptance by the customer. We exclude rigs that are not operating under contract, such as those that are stacked. Rig utilization—We present our rig utilization as an indicator of our ability to secure work for our fleet. Rig utilization is defined as the total number of operating days divided by the total number of rig calendar days in the measurement period, expressed as a percentage. The rig utilization rates for our fleet were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended ​ ​ ​ June 30, ​ March 31, ​ June 30, ​ ​ ​ 2026 ​ 2026 ​ 2025 Rig utilization ​ ​ ​ ​ ​ ​ ​ ​ ​ Ultra-deepwater floaters ​ 72.6 % ​ 82.1 % ​ 64.7 % ​ Harsh environment floaters ​ 94.2 % ​ 100.0 % ​ 75.3 % ​ Total fleet average rig utilization ​ 78.2 % ​ 86.7 % ​ 67.3 % ​ Our rig utilization rate declines as a result of idle and stacked rigs and during shipyard, contract preparation and mobilization periods. We include newbuilds in the calculation when the rigs commence operations upon acceptance by the customer. We remove a rig from the calculation upon disposal or classification as held for sale, unless we continue to operate the rig, in which case we remove the rig upon completion or novation of the contract. Accordingly, our rig utilization can increase when we remove idle or stacked units from our fleet. - 16 - Table of Contents Operating Results Three months ended June 30, 2026 compared to the three months ended June 30, 2025 The following is an analysis of our operating results. See “—Performance and Other Key Indicators” for definitions of operating days, average daily revenue, revenue efficiency and rig utilization. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three months ended June 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ Change ​ ​ ​ % Change ​ ​ ​ (in millions, except day amounts and percentages) ​ ​ Operating days ​ ​ 1,922 ​ ​ 2,040 ​ ​ ​ (118) ​ (6) % ​ Average daily revenue $ 472,500 ​ ​ $ 458,600 ​ ​ $ 13,900 ​ 3 % ​ Revenue efficiency ​ ​ 97.0 % ​ ​ 96.6 % ​ ​ ​ ​ ​ ​ ​ Rig utilization ​ ​ 78.2 % ​ ​ 67.3 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract drilling revenues $ 966 ​ ​ $ 988 ​ ​ $ (22) ​ (2) % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating and maintenance expense ​ ​ (608) ​ ​ ​ (599) ​ ​ ​ (9) ​ (2) % ​ Depreciation and amortization expense ​ ​ (148) ​ ​ ​ (175) ​ ​ ​ 27 ​ 15 % ​ General and administrative expense ​ ​ (56) ​ ​ ​ (49) ​ ​ ​ (7) ​ (14) % ​ Loss on impairment of assets ​ ​ — ​ ​ ​ (1,136) ​ ​ ​ 1,136 ​ nm ​ ​ Gain (loss) on disposal of assets, net ​ ​ (2) ​ ​ ​ 7 ​ ​ ​ (9) ​ nm ​ ​ Operating income (loss) ​ ​ 152 ​ ​ ​ (964) ​ ​ ​ 1,116 ​ nm ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other income (expense), net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ ​ 12 ​ ​ ​ 10 ​ ​ ​ 2 ​ 20 % ​ Interest expense ​ ​ 20 ​ ​ ​ (112) ​ ​ ​ 132 ​ nm ​ ​ Other, net ​ ​ — ​ ​ ​ (27) ​ ​ ​ 27 ​ nm ​ ​ Income (loss) before income taxes ​ ​ 184 ​ ​ ​ (1,093) ​ ​ ​ 1,277 ​ nm ​ ​ Income tax (expense) benefit ​ ​ (14) ​ ​ ​ 155 ​ ​ ​ (169) ​ nm ​ ​ Net income (loss) $ 170 ​ ​ $ (938) ​ ​ $ 1,108 ​ nm ​ ​ “nm” means not meaningful. Contract drilling revenues—Contract drilling revenues decreased for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to approximately $50 million resulting from decreased rig utilization for the comparable fleet, considering six idle rigs in the earlier-year utilization rate that were classified as held for sale and sold subsequent to June 30, 2025. This decrease was partially offset by the following increases: (a) approximately $15 million resulting from higher average daily revenues, (b) approximately $10 million resulting from increased reimbursement revenues, and (c) approximately $5 million resulting from improved revenue efficiency for the active fleet. Costs and expenses—Operating and maintenance costs and expenses increased for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to the following increases: (a) approximately $15 million resulting from personnel costs and (b) approximately $10 million resulting from reimbursable costs. These increases were partially offset by the following decreases: (a) approximately $5 million resulting from rigs sold, (b) approximately $5 million resulting from lower in-service costs related to additional services and contract preparation cost recognition, and (c) approximately $5 million resulting from lower asset maintenance costs. Depreciation and amortization expense decreased for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to a $30 million reduction resulting from rigs sold or classified as held for sale. General and administrative costs and expenses increased for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to the following: (a) $11 million of acquisition costs and (b) $3 million of integration costs, both of which recognized in the current-year period with no comparable activity in the earlier year, partially offset by (c) $7 million resulting from decreased personnel costs. Impairment of assets—In the three months ended June 30, 2025, we recognized a loss on impairment of the ultra-deepwater floaters Discoverer Luanda and GSF Development Driller I, together with related assets, which we determined were impaired at the time we classified them as held for sale, and the ultra-deepwater floaters Development Driller III and Discoverer Inspiration, together with related assets, which were previously classified as held for sale and determined to be further impaired. Disposal of assets—In the three months ended June 30, 2026 and 2025, we recognized a net loss and a net gain, respectively, on disposal of assets unrelated to rig sales. Other income and expense—Interest expense decreased in the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to the following: (a) $105 million decreased interest resulting from changes to the fair value of the bifurcated compound exchange feature embedded in the indenture governing the 4.625% senior guaranteed exchangeable bonds due September 2029 (the “4.625% Exchangeable Bonds”) and (b) $36 million decreased interest resulting from debt repaid as scheduled or early retired, partially offset by (c) $10 million increased interest resulting from debt issued in the earlier year. - 17 - Table of Contents Other expense, net, decreased in the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to a loss of $24 million associated with the issuance of additional Transocean Ltd. shares to certain holders of 4.00% senior guaranteed exchangeable bonds due December 2025 (the “4.00% Exchangeable Bonds”) in the earlier year with no comparable activity in the current-year period. Income tax expense or benefit—In the three months ended June 30, 2026 and 2025, our effective tax rate was 7.8% percent and 14.2 percent, respectively, based on income or loss before income taxes. In the three months ended June 30, 2026 and 2025, the effect of various discrete period tax items was a net tax benefit of $24 million and $203 million, respectively. In the three months ended June 30, 2026, such discrete items were primarily related to valuation allowance adjustments. In the three months ended June 30, 2025, such discrete items included changes to various uncertain tax positions, valuation allowances and rig basis changes related to impairment. In the three months ended June 30, 2026 and 2025, our effective tax rate, excluding discrete items, was 19.4 percent and 70.0 percent, respectively, based on income before income taxes. Due to our operating activities and organizational structure, our income tax expense or benefit does not change proportionally with our income or loss before income taxes. We may have subsidiaries with tax expense on taxable earnings that exceeds the tax benefits in other jurisdictions, or vice versa, which sometimes results in a negative effective tax rate or unusually large effective tax rates relative to consolidated income or loss before income tax expense or benefit. Our earnings are unevenly distributed across jurisdictions and may experience variability in timing among interim periods throughout the year, and such variability may influence the allocation of income tax expense or benefit to the respective interim period. The annual effective tax rate used to allocate income tax expense or benefit to interim periods may also be influenced by the removal of loss jurisdictions from the calculations. Our rig operating structures further complicate our tax calculations, especially in instances where we have more than one operating structure for the taxing jurisdiction and, thus, more than one method of calculating taxes depending on the operating structure utilized by the rig under the contract. Six months ended June 30, 2026 compared to the six months ended June 30, 2025 The following is an analysis of our operating results. See “—Performance and Other Key Indicators” for definitions of operating days, average daily revenue, revenue efficiency and rig utilization. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended June 30, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ Change ​ ​ ​ % Change ​ ​ ​ (in millions, except day amounts and percentages) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating days ​ ​ 4,030 ​ ​ 3,980 ​ ​ ​ 50 ​ 1 % ​ Average daily revenue $ 474,100 ​ ​ $ 451,300 ​ ​ $ 22,800 ​ 5 % ​ Revenue efficiency ​ ​ 97.2 % ​ ​ 96.1 % ​ ​ ​ ​ ​ ​ ​ Rig utilization ​ ​ 82.5 % ​ ​ 65.3 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Contract drilling revenues $ 2,047 ​ ​ $ 1,894 ​ ​ $ 153 ​ 8 % ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating and maintenance expense ​ ​ (1,214) ​ ​ ​ (1,217) ​ ​ ​ 3 ​ — % ​ Depreciation and amortization expense ​ ​ (291) ​ ​ ​ (351) ​ ​ ​ 60 ​ 17 % ​ General and administrative expense ​ ​ (105) ​ ​ ​ (99) ​ ​ ​ (6) ​ (6) % ​ Loss on impairment of assets ​ ​ — ​ ​ ​ (1,136) ​ ​ ​ 1,136 ​ nm ​ ​ Gain on disposal of assets, net ​ ​ 2 ​ ​ ​ 9 ​ ​ ​ (7) ​ (78) % ​ Operating income (loss) ​ ​ 439 ​ ​ ​ (900) ​ ​ ​ 1,339 ​ nm ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Other income (expense), net ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ ​ 22 ​ ​ ​ 18 ​ ​ ​ 4 ​ 22 % ​ Interest expense ​ ​ (256) ​ ​ ​ (228) ​ ​ ​ (28) ​ (12) % ​ Loss on retirement of debt ​ ​ (11) ​ ​ ​ — ​ ​ ​ (11) ​ nm ​ ​ Other, net ​ ​ 7 ​ ​ ​ (23) ​ ​ ​ 30 ​ nm ​ ​ Income (loss) before income taxes ​ ​ 201 ​ ​ ​ (1,133) ​ ​ ​ 1,334 ​ nm ​ ​ Income tax benefit ​ ​ 40 ​ ​ ​ 116 ​ ​ ​ (76) ​ (66) % ​ Net income (loss) $ 241 ​ ​ $ (1,017) ​ ​ $ 1,258 ​ nm ​ ​ “nm” means not meaningful. Contract drilling revenues—Contract drilling revenues increased for the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to the following: (a) approximately $80 million resulting from higher average daily revenues, (b) approximately $30 million resulting from increased utilization, (c) approximately $25 million resulting from increased reimbursement revenues, and (d) approximately $20 million resulting from improved revenue efficiency for the active fleet. Costs and expenses—Operating and maintenance costs and expenses decreased for the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to the following: (a) a non-cash loss of $34 million in the earlier year resulting from an unfavorable legal outcome, (b) approximately $10 million resulting from rigs sold, and (c) approximately $10 million resulting from lower asset maintenance costs. These decreases were partially offset by the following increases: (a) approximately $25 million resulting from reimbursable costs and (b) approximately $25 million resulting from personnel costs. - 18 - Table of Contents Depreciation and amortization expense decreased for the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to a $64 million reduction resulting from rigs sold or classified as held for sale. General and administrative costs and expenses increased for the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to the following (a) $17 million of acquisition costs and (b) $3 million of integration costs, both of which recognized in the current-year period with no comparable activity in the earlier year, partially offset by (c) $9 million resulting from decreased personnel costs and (d) $3 million of decreased legal and professional fees. Impairment of assets—In the six months ended June 30, 2025, we recognized a loss on impairment of Discoverer Luanda and GSF Development Driller I, together with related assets, which we determined were impaired at the time we classified them as held for sale, and Development Driller III and Discoverer Inspiration, together with related assets, which were previously classified as held for sale and determined to be further impaired. Disposal of assets—In the six months ended June 30, 2026, we recognized a net gain of $4 million associated with the disposal of two ultra-deepwater drillships and related assets. In the six months ended June 30, 2026 and 2025, we recognized a net loss of $2 million and a net gain of $9 million, respectively, on disposal of assets unrelated to rig sales. Other income and expense—Interest expense increased in the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to the following: (a) $84 million increased interest resulting from changes to the fair value of the bifurcated compound exchange feature embedded in the indenture governing the 4.625% Exchangeable Bonds, (b) $20 million increased interest resulting from debt issued in the earlier year, partially offset by (c) $80 million decreased interest resulting from debt repaid as scheduled or early retired. In the six months ended June 30, 2026, we recognized a loss on retirement of the 8.375% Senior Secured Notes. Other income, net, increased in the six months ended June 30, 2026, compared to the six months ended June 30, 2025, primarily due to the following: (a) a loss of $24 million associated with the issuance of additional Transocean Ltd. shares to certain holders of the 4.00% Exchangeable Bonds in the earlier year with no comparable activity in the current-year period and (b) increased income of $5 million associated with our investments in the debt and equity of unconsolidated affiliates. Income tax expense or benefit—In the six months ended June 30, 2026 and 2025, our effective tax rate was (19.8) percent and 10.3 percent, respectively, based on income or loss before income taxes. In the six months ended June 30, 2026 and 2025, the effect of various discrete period tax items was a net tax benefit of $137 million and $189 million, respectively. In the six months ended June 30, 2026, such discrete items included changes to operating structures and valuation allowances. In the six months ended June 30, 2025, such discrete items included changes to various uncertain tax positions, valuation allowances and rig basis changes related to impairment. In the six months ended June 30, 2026 and 2025, our effective tax rate, excluding discrete items, was 42.8 percent and 268.9 percent, respectively, based on income or loss before income taxes. Due to our operating activities and organizational structure, our income tax expense or benefit does not change proportionally with our income or loss before income taxes. We may have subsidiaries with tax expense on taxable earnings that exceeds the tax benefits in other jurisdictions, or vice versa, which sometimes results in a negative effective tax rate or unusually large effective tax rates relative to consolidated income or loss before income tax expense or benefit. Our earnings are unevenly distributed across jurisdictions and may experience variability in timing among interim periods throughout the year, and such variability may influence the allocation of income tax expense or benefit to the respective interim period. The annual effective tax rate used to allocate income tax expense or benefit to interim periods may also be influenced by the removal of loss jurisdictions from the calculations. Our rig operating structures further complicate our tax calculations, especially in instances where we have more than one operating structure for the taxing jurisdiction and, thus, more than one method of calculating taxes depending on the operating structure utilized by the rig under the contract. Liquidity and Capital Resources Sources and uses of cash In the six months ended June 30, 2026, our primary source of cash was net cash provided by operating activities. Our primary uses of cash were debt repayments and capital expenditures. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ ​ ​ 2026 ​ ​ 2025 ​ ​ Change ​ ​ (in millions) ​ Cash flows from operating activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) $ 241 $ (1,017) $ 1,258 ​ Non-cash items, net ​ ​ 280 ​ ​ 1,328 ​ ​ (1,048) ​ Changes in operating assets and liabilities, net ​ ​ (121) ​ ​ (157) ​ ​ 36 ​ ​ $ 400 $ 154 $ 246 ​ Net cash provided by operating activities increased primarily due to (a) increased cash received from customers and (b) reduced cash paid for interest. - 19 - Table of Contents ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ ​ ​ 2026 ​ ​ 2025 ​ ​ Change ​ ​ (in millions) ​ Cash flows from investing activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Capital expenditures $ (52) $ (84) $ 32 ​ Investment in equity of unconsolidated affiliate ​ ​ (2) ​ ​ — ​ ​ (2) ​ Proceeds from disposal of assets, net of costs to sell ​ ​ 26 ​ ​ 10 ​ ​ 16 ​ Proceeds from disposal of investment in debt or equity of unconsolidated affiliates ​ ​ 13 ​ ​ 4 ​ ​ 9 ​ ​ $ (15) $ (70) $ 55 ​ Net cash used in investing activities decreased primarily due to (a) decreased capital expenditures, (b) increased proceeds from disposal of assets, primarily resulting from the completion of the sale of two ultra-deepwater floaters in the current-year period, and (c) proceeds from disposal of an investment in a note receivable from an unconsolidated affiliate in the current-year period relative to proceeds from disposal of an investment in equity of an unconsolidated affiliate in the earlier year. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six months ended ​ ​ ​ ​ ​ ​ June 30, ​ ​ ​ ​ ​ ​ ​ ​ 2026 ​ ​ ​ 2025 ​ ​ ​ Change ​ ​ (in millions) ​ Cash flows from financing activities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Repayments of debt ​ $ (586) ​ $ (240) ​ $ (346) ​ Other, net ​ ​ (1) ​ ​ (13) ​ ​ 12 ​ ​ $ (587) $ (253) $ (334) ​ Net cash used in financing activities increased primarily due to increased cash used to repay debt, primarily resulting from the redemption of the outstanding $358 million aggregate principal amount of the 8.375% Senior Secured Notes in current-year period. Sources and uses of liquidity Overview—We expect to use existing unrestricted cash balances, cash flows from operating activities, borrowings under our Secured Credit Facility, proceeds from the disposal of assets or proceeds from the issuance of debt or shares to fulfill anticipated near-term obligations, which may include capital expenditures, working capital and other operational requirements, scheduled debt installments and maturities or other debt-related deposits or reservations of unrestricted cash. At June 30, 2026, we had $509 million in unrestricted cash and cash equivalents and $286 million in restricted cash and cash equivalents. We have generated positive cash flows from operating activities over recent years and, although we cannot provide assurances, we expect that such cash flows will continue to be positive over the next year. For example, among other factors, if we incur costs for reactivation or contract preparation of multiple rigs or to otherwise assure the marketability of our fleet or general economic, financial, industry or business conditions deteriorate, our cash flows from operations may be reduced or negative. We have a Secured Credit Facility that provides us with a borrowing capacity of $510 million through its maturity on June 22, 2028. Our Secured Credit Facility, which is secured by, among other things, a lien on eight of our ultra-deepwater drillships and two of our harsh environment semisubmersibles, contains certain restrictive covenants, including a minimum guarantee coverage ratio of 3.0 to 1.0, a minimum collateral coverage ratio of 2.1 to 1.0 and a minimum liquidity requirement of $200 million, among others. The Secured Credit Facility also restricts the ability of Transocean Ltd. and certain of our subsidiaries to, among other things, merge, consolidate or otherwise make changes to the corporate structure, incur liens, incur additional indebtedness, enter into transactions with affiliates and permits, subject to certain conditions, us to pay dividends and repurchase our shares. For more information about our Secured Credit Facility and our outstanding debt instruments, see Notes to Condensed Consolidated Financial Statements—Note 6—Debt. Although we currently anticipate relying on these sources of liquidity, including cash flows from operating activities and borrowings under our Secured Credit Facility, among others, we may in the future consider establishing additional financing arrangements with banks or other capital providers and subject to market conditions and other factors, we may be required to provide collateral for any such future financing arrangements. Our secured indentures include collateral rig leverage ratios. During periods where collateral rigs have experienced reduced levels of operating efficiency or utilization, we have in the past deposited cash into the applicable debt service reserve account and taken other actions, including obtaining consents of holders of certain of our secured debt, as applicable, in order to satisfy the applicable collateral rig leverage ratio, and we may in the future take such actions from time to time, as necessary. Debt and equity markets—From time to time, we seek to access the capital markets in connection with our ongoing efforts to prudently manage our capital structure and improve our liquidity position. For example, we have completed multiple debt and equity transactions, including tender offers, redemptions, exchanges and retirement of existing debt. Subject to then-existing market conditions and our expected liquidity needs, among other factors, we may also use existing unrestricted cash balances, cash flows from operating activities, or proceeds from asset sales to manage our capital structure, including by purchasing or exchanging any of our debt or equity securities in the open market, in privately negotiated transactions, or through tender or exchange offers, or by redeeming any of our outstanding debt securities pursuant to the terms of the applicable governing document, if applicable. Any future purchases, exchanges or other transactions may be on the same terms or on terms that are more or less favorable to holders than the terms of any prior transaction. We can provide no assurance as to which, if any, of these alternatives, or combinations thereof, we may choose to pursue in the future, if at - 20 - Table of Contents all, or as to the timing with respect to any future transactions. For more information about our debt and equity transactions, see Notes to Condensed Consolidated Financial Statements—Note 6—Debt and Note 10—Equity. Our ability and willingness to access the debt and equity markets is a function of a variety of factors, including, among others, general economic, industry or market conditions, market perceptions of us and our industry and credit rating agencies’ views of our debt. General economic or market conditions could have an adverse effect on our business and financial position and on the business and financial position of our customers, suppliers and lenders and could affect our ability to access the capital markets on acceptable terms or at all and our future need or ability to borrow under our Secured Credit Facility. In addition to our potential sources of funding, the effects of such global events could impact our liquidity or cause us to need to alter our allocation or sources of capital, implement further cost reduction measures and change our financial strategy. Additionally, the rating of our long-term debt is below investment grade, which is causing us to experience increased fees and interest rates under our Secured Credit Facility and indentures governing certain of our senior notes. Future downgrades may further restrict our ability to access the debt market for sources of capital and may negatively impact the cost of such capital at a time when we would like, or need, to access such markets, which could have an impact on our flexibility to react to changing economic and business conditions. Drilling fleet—From time to time, we review possible acquisitions of businesses and drilling rigs, as well as noncontrolling ownership interests in other companies, and we may make significant future capital commitments for such purposes. We may also consider investments related to major rig upgrades, new rig construction, or the acquisition of a rig under construction. Any such acquisition or investment has involved, and in the future could involve, the payment by us of a substantial amount of cash or the issuance of a substantial number of additional shares or other securities. Our failure to subsequently secure drilling contracts in these instances, if not already secured, could have an adverse effect on our results of operations or cash flows. For information about our Agreement to acquire Valaris, see Notes to Consolidated Financial Statements—Note 1—Business. The ultimate amount of our capital expenditures is partly dependent upon financial market conditions, the actual level of operational and contracting activity, the costs associated with the current regulatory environment and customer-requested capital improvements and equipment for which the customer agrees to reimburse us. As with any major shipyard project that takes place over an extended period, the actual costs, the timing of expenditures and the project completion date may vary from estimates based on numerous factors, including actual contract terms, weather, exchange rates, shipyard labor conditions, availability of suppliers to recertify equipment and market demand for required components and resources. We intend to fund the cash requirements for our projected capital expenditures by using available cash balances, cash generated from operations and asset sales, borrowings under our Secured Credit Facility and financing arrangements with banks or other capital providers. Economic conditions and other factors could impact the availability of these sources of funding. From time to time, we may review the possible disposition of certain drilling assets. In the six months ended June 30, 2026, we completed the disposal of two ultra-deepwater drillships, together with related assets, in sales for recycling. In July 2026, we completed the sale of one harsh environment semisubmersible and related assets in a sale for recycling. Considering market conditions, we may identify additional lower-specification drilling units to be sold for scrap, recycling or alternative purposes. See Notes to Condensed Consolidated Financial Statements—Note 5—Long-Lived Assets. Contractual obligations and other commercial commitments—As of June 30, 2026, with exception to our redemption and early retirement of the outstanding $358 million aggregate principal amount of the 8.375% Senior Secured Notes, there have been no material changes to our contractual obligations or other commercial commitments as previously disclosed in “Part II. Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations” in our annual report on Form 10-K for the year ended December 31, 2025. For additional information about our debt obligations, including scheduled maturities and early retirement, see Notes to Condensed Consolidated Financial Statements—Note 6—Debt. Critical Accounting Policies and Estimates As of June 30, 2026, there have been no material changes to the critical accounting policies and estimates that we use as a basis for applying judgments, assumptions and estimates to prepare our condensed consolidated financial statements, as previously disclosed in “Part II. Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies and Estimates” in our annual report on Form 10-K for the year ended December 31, 2025. Other Matters Regulatory matters We occasionally receive inquiries from governmental regulatory agencies regarding our operations around the world, including inquiries with respect to various tax, environmental, regulatory and compliance matters. To the extent appropriate under the circumstances, we investigate such matters, respond to such inquiries and cooperate with the regulatory agencies. See Notes to Condensed Consolidated Financial Statements—Note 9—Contingencies. Tax matters We conduct operations through our various subsidiaries in countries throughout the world. Each country has its own tax regimes with varying nominal rates, deductions and tax attributes that are subject to changes resulting from new legislation, interpretation or guidance. - 21 - Table of Contents From time to time, as a result of these changes, we may revise previously evaluated tax positions, which could cause us to adjust our recorded tax assets and liabilities. Tax authorities in certain jurisdictions are examining our tax returns and, in some cases, have issued assessments. We intend to defend our tax positions vigorously. Although we can provide no assurance as to the outcome of the aforementioned changes, examinations or assessments, we do not expect the ultimate liability to have a material adverse effect on our financial position or results of operations; however, it could have a material adverse effect on our cash flows. See Notes to Condensed Consolidated Financial Statements—Note 7—Income Taxes.