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

Momenta Pharmaceuticals, Inc. (symbol: MNTA) was one of the worst losers of
the trading day today (2015-08-20), losing -10.52%. The number of shares
that changed hands was 786,265, or about 1 times the average daily volume
in the stock.
The closing price was $20.16, amounting to a market cap of $1,370,000,000,
about -21.13% off the highest price in the last 12 months. The stock has
been trading at a range between $9.38 and $25.56.
MNTA is in the Biotechnology: Biological Products (No Diagnostic
Substances) industry, part of the Health Care sector. It first went public
in 2004.