Energy stocks drop as oil dips below $90 By: MarketWatch January 06, 2011 at 10:09 AM EST Energy stocks move lower in early trading, even as Chesapeake rises on plans to reduce debt, and Exxon draws upgrade. Read More >> Related Stocks: BP Plc ADR Chesapeake Energy Exxon Mobil Halliburton Co Pioneer Natural Resources Standard & Poors 500 Transocean Ltd