Management Team

Mr. Block has served as the Company’s Chief Executive Officer and a member of the Sphere 3D board of directors since June 1, 2026. Mr. Block is a seasoned executive with more than 20 years of experience across finance, accounting, operations, and sales. From July 2025 to May 30, 2025, Mr. Block served as Chief Executive Officer of Cathedra Bitcoin Inc. (“Cathedra”) and Chairman of the Cathedra Board. From December 2021 to November 2023, he served as the Chief Financial Officer of US Bitcoin Corp.; prior to this role, from September 2021 to November 2021, he served as US Bitcoin Corp.’s Chief Business Officer. US Bitcoin Corp. merged with Hut 8 Corp. on November 30, 2023. Prior to US Bitcoin Corp., from February 2015 to August 2021 he served as CFO, and then CEO, of Collegewise, one of the US’s largest college admissions companies. From 2005 to 2013, he served in a number of roles at Credit Suisse, including as a Vice President on the Institutional Fixed Income Sales team, where he specialized in interest rate derivatives and hedging transactions. He has served on the board of the Young Presidents Organization Orange County Chapter. He received his Bachelor of Business Administration with concentrations in Finance and Accounting and a minor in Statistics from the University of Michigan Ross School of Business.

Mr. Kalbfleisch has served as the Company’s Chief Financial Officer and Secretary of the Company since December 1, 2014 and as a member of the Sphere 3D board of directors since June 1, 2026. Mr. Kalbfleisch served as the Company’s Chief Executive Officer from November 5, 2025 to May 31, 2026 and as the Company's Acting Chief Executive Officer from January 31, 2025 to November 4, 2025. Mr. Kalbfleisch also served as Chief Financial Officer of Overland Storage, Inc. (“Overland”) from February 2008 until his resignation from Overland on July 19, 2022. Previously, Mr. Kalbfleisch served in various other roles at Overland since July 2007, including Senior Vice President, Secretary and Vice President of Finance. Prior to joining Overland, he was a manufacturing budget analyst for McDonnell Douglas Corp. Mr. Kalbfleisch also served on the board of Paladin Group. Mr. Kalbfleisch holds a Bachelor of Arts in Business from Point Loma Nazarene University and a Master of Business Administration from the University of San Diego.

Ms. Reppas has served as the Company's Chief Accounting Officer since December 17, 2025 and Vice President of Accounting and Finance from April 2025 to December 2025.  Ms. Reppas also served as the Company's Vice President of Finance and Corporate Controller from November 2017 to January 2019 and Corporate Controller from December 2014 to January 2019. From January 2019 to July 2021, Ms. Reppas served as Corporate Controller of Ra Medical Systems, Inc. (NYSE:RMED), Chief Accounting Officer and Corporate Controller from January 2020 to July 2021 and Vice President, Chief Accounting Officer and Corporate Controller from March 2021 to July 2021. Since July 2021 Ms. Reppas has been a fractional Chief Accounting Officer, Controller and advisor to small public and private companies. In this capacity she has been responsible for accounting and technical accounting functions, SEC compliance, managed audit, tax and banking audits, reviews and compliance, and supported capital raises and mergers and acquisition activities. Ms. Reppas is a former auditor with Deloitte & Touche LLP. Ms. Reppas is an active Certified Public Accountant and holds a Bachelor of Arts, business economics with accounting emphasis, from the University of California at Santa Barbara.