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

Seres Therapeutics, Inc. (symbol: MCRB) was one of the worst losers of the
trading day today (2015-12-23), losing -4.87%. The number of shares that
changed hands was 495,100, or about 2 times the average daily volume in the
stock.
The closing price was $35.77, amounting to a market cap of $1,400,000,000,
about -31.21% off the highest price in the last 12 months. The stock has
been trading at a range between $25.0 and $52.0.
MCRB is in the n/a industry, part of the n/a sector.