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

Achillion Pharmaceuticals, Inc. (symbol: ACHN) was one of the worst losers
of the trading day today (2016-06-17), losing -6.37%. The number of shares
that changed hands was 3,384,161, or about 2 times the average daily volume
in the stock.
The closing price was $8.52, amounting to a market cap of $1,160,000,000,
about -22.19% off the highest price in the last 12 months. The stock has
been trading at a range between $5.57 and $10.95.
ACHN is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2006.