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

PTC Therapeutics, Inc. (symbol: PTCT) was one of the worst losers of the
trading day today (2015-11-26), losing -7.02%. The number of shares that
changed hands was 1,694,602, or about 2 times the average daily volume in
the stock.
The closing price was $29.52, amounting to a market cap of $1,000,000,000,
about -62.5% off the highest price in the last 12 months. The stock has
been trading at a range between $22.67 and $78.72.
PTCT is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2013.