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

Hansen Medical, Inc. (symbol: HNSN) was one of the worst losers of the
trading day today (2015-09-23), losing -12.2%. The number of shares that
changed hands was 300,178, or about 15 times the average daily volume in
the stock.
The closing price was $4.39, amounting to a market cap of $828,750,000,
about -64.31% off the highest price in the last 12 months. The stock has
been trading at a range between $3.79 and $12.3.
HNSN is in the Industrial Specialties industry, part of the Health Care
sector. It first went public in 2006.