RIG: 10-Q financial filing

Transocean Ltd._September 30, 2026 Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ​ ​ FORM 10-Q (Mark one) ☑ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2026 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _____ to _____ ​ ​ Commission file number 001-38373 ​ Transocean Ltd. (Exact name of registrant as specified in its charter) ​ ​ Switzerland 98-0599916 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) ​ ​ Turmstrasse 30 Steinhausen , Switzerland 6312 (Address of principal executive offices) (Zip Code) ​ ​ ​ + 41 ( 41 ) 749-0500 (Registrant’s telephone number, including area code) ​ ​ ​ Securities registered pursuant to Section 12(b) of the Act: ​ ​ ​ ​ ​ ​ Title of each class Trading symbol Name of each exchange on which registered Shares, $0.10 par value RIG New York Stock Exchange ​ Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes þ No ◻ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes þ No ◻ Indicate by check mark whether the registrant is a large accelerat