Guess what swing producer will affect oil prices By: CNBC.com News April 20, 2015 at 09:52 AM EDT US oil companies have quickly become the new swing factor in the oil market. How they react to the crash will be key to future oil prices. Read More >> Related Stocks: BlackRock ConocoPhillips Exxon Mobil Occidental Petroleum Oppenheimer Holdings Royal Dutch Shell Cl B ADR Totalenergies Se ADR