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

Collegium Pharmaceutical, Inc. (symbol: COLL) was one of the worst losers
of the trading day today (2015-12-31), losing -4.31%. The number of shares
that changed hands was 188,086, or about 1 times the average daily volume
in the stock.
The closing price was $27.5, amounting to a market cap of $568,920,000,
about -10.07% off the highest price in the last 12 months. The stock has
been trading at a range between $11.92 and $30.58.
COLL is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2015.