Hollis is the Chairman of Veritas, overseeing the strategic direction of the company.

Hollis began his career with Cobra Oil & Gas and also worked as an oil field pumper for his father and grandfather. He made his first significant oil discovery in 1990 in Concho County, Texas. He has built and sold various companies since then: founding Hollis R. Sullivan, Inc. in 1990, later selling its Barnett Shale assets to Encana Corporation and XTO Energy Inc., and Veritas in 2011, eventually merging with a subsidiary of Double Eagle Energy and later selling its Permian Basin assets to Parsley Energy, Inc. in 2017.

Hollis earned a Bachelor of Business Administration in accounting from Midwestern State University.

He previously served as chairman of the Texas Alliance of Energy Producers, where he remains an active member, along with being an active member of the Fort Worth Wildcatters and IPAA.