Midstream companies transport crude oil, natural gas, refined products, coal and other commodities through pipeline systems and shipping and trucking of both feedstock and end-use products. Their activities also include storing various commodities, significant hedging and price risk management products and services and marketing (primarily wholesale) for virtually all types of feedstock and end-use products.

Midstream assets typically require significant capital initially, but ongoing capital requirements are modest relative to many other segments. Midstream companies typically generate the majority of their revenues, earnings and returns through tariff agreements with shippers. Such agreements typically call for a fee based on the volumes shipped. As a result, midstream economics generally are significantly less exposed to commodity price volatility. Many midstream companies also engage in merchant and risk management activities pursuant to which they will often take principal positions in specific commodities and assume any related price exposure.