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

Semgroup Corporation Class A Co (symbol: SEMG) was one of the worst losers
of the trading day today (2016-01-18), losing -13.98%. The number of shares
that changed hands was 2,525,801, or about 4 times the average daily volume
in the stock.
The closing price was $19.75, amounting to a market cap of $867,660,000,
about -77.3% off the highest price in the last 12 months. The stock has
been trading at a range between $18.48 and $86.99.
SEMG is in the Oilfield Services/Equipment industry, part of the Energy
sector.
Looking at its valuation, the stock is now trading at 22.94 times earnings.