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

Diamond Offshore Drilling, Inc. (symbol: DO) was one of the worst losers of
the trading day today (2016-03-29), losing -5.04%. The number of shares
that changed hands was 3,348,160, or about 1 times the average daily volume
in the stock.
The closing price was $21.46, amounting to a market cap of $2,940,000,000,
about -40.31% off the highest price in the last 12 months. The stock has
been trading at a range between $14.18 and $35.95.
DO is in the Oil & Gas Production industry, part of the Energy sector. It
first went public in 1995.