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

Ultragenyx Pharmaceutical Inc. (symbol: RARE) was one of the worst losers
of the trading day today (2016-01-27), losing -12.0%. The number of shares
that changed hands was 1,200,691, or about 3 times the average daily volume
in the stock.
The closing price was $64.83, amounting to a market cap of $2,520,000,000,
about -52.7% off the highest price in the last 12 months. The stock has
been trading at a range between $49.08 and $137.05.
RARE is in the Major Pharmaceuticals industry, part of the Health Care
sector. It first went public in 2014.