AAMAntero Midstream Corporation

Antero Midstream gathers gas from one producer's wells and charges for volume.

The company owns gathering pipelines, compressor stations and water systems for fracturing. It neither buys nor sells gas: income comes from fees on volume moved, so the gas price affects it only indirectly — through the producer's decision to drill or hold back.

The defining feature is concentration: the system was built for one customer, and its utilisation depends entirely on that customer's plans. That is at once stability, fixed by long-term contracts, and a risk that cannot be diversified away. Risks: the drilling pace of a single client, permits for new facilities and debt. A dividend is paid.