$SDRL is one of biggest losers #stocks today. read more:

Seadrill Limited Ordinary Share (symbol: SDRL) was one of the worst losers
of the trading day today (2015-12-08), losing -10.25%. The number of shares
that changed hands was 18,134,935, or about 2 times the average daily
volume in the stock.
The closing price was $4.38, amounting to a market cap of $2,160,000,000,
about -71.63% off the highest price in the last 12 months. The stock has
been trading at a range between $4.29 and $15.44.
SDRL is in the Oil & Gas Production industry, part of the Energy sector.